WORLD'S LARGEST -SELLING ELECTRONICS … · Soviet chess champion agrees to endorse American chess computer in surprise w u . answer to computer challenge. The JS&A Chess Computer

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t0DUY a personal computer. Suddenly everyone is talking about personal computers. Are you ready for one? The best way to find out is to read Apple Computer's "Consumer Guide to Personal Computing." It will answer your unanswered questions and show you how useful and how much fun personal computers can be. And it will help you choose a computer that meets your personal needs.

who uses personal computers. Thousands of people have already discovered the Apple computer-businessmen, students, hobbyists. They're using their Apples for financial management, complex problem solving-and just plain fun. You can use your Apple to analyze the stock market, manage your personal finances, control your home environment, and to invent an unlimited number of sound and action video games. That's just the beginning.

What to look for. Once you've unlocked the power of the personal computer, you'll be

using your Apple in ways you never dreamed of. That's when the capabilities of the computer you buy will really count. You don't want to be limited by the availability of pre-programmed cartridges. You'll want a computer, like Apple, that you can also program yourself. You don't want to settle for a black and white display. You'll want a computer, like Apple, that can turn any color tv into a dazzling array of color graphics.* The more you learn about computers, the more your imagination will demand. So you'll want a computer that can grow with you as your skill and experience with computers grows. Apple's the one.

How to get one. The quickest way is to get a free copy of the Consumer Guide to Personal Computing. Get yours by calling 800/538-9696. Or by writing us. Then visit your local Apple dealer. We'll give you his name and address when you call.

'Apple II plugs into any standard TV using an inexpensive modulator (not included).

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Mr. Karpov and our computer.

The new $100 JS&A chess computer will make computer chess an affordable game for the American consumer.

Anatoli Karpov is the undisputed World Chess Champion. Last month, JS&A chal- lenged Karpov to play against our chess computer. We offered him $50,000 and a percentage of each unit we sold if he beat our game.

Karpov rejected our offer and quite frankly, we were at a loss to explain why.

Our concept was simple. If Karpov played against our computer, he would focus worldwide attention on our product. This attention would increase its sales and win or lose, we would sell more computers.

We had to sell more computers. We wanted our unit to sell for $100 even though units with similar capabilities were selling for up to $400. But we had to do two things to keep our low price: First, we had to manufacture our unit in Hong Kong where labor costs are very low. Secondly, we had to sell large quantities to keep production costs down.

When we first announced our challenge, the Soviets rejected it. Could Karpov have been afraid to play against it? Or was the circus -like atmosphere that might surround the event not in keeping with the prestige of the coveted world title, even if Karpov won?

Quite honestly, we had no idea. So we asked Karpov for an explanation and got one. Here's what he said:

"I can appreciate your desire to sell the JS&A Chess Computer but you have missed an important point of the entire challenge. It

took somebody to program the unit and since I

am the world's chess champion, it is highly unlikely that the programmer person could beat me. You Americans have a saying, "Garbage in, garbage out."

Karpov continued, "Your unit is definitely a good product. I played several games at level six and found it to be a challenge even for me. What I like about your unit is that it is priced low enough so that most Americans can afford the unit and this will help promote chess."

Soviet chess champion agrees to endorse American chess computer in surprise

w u . answer to computer challenge.

The JS&A Chess Computer indeed has six levels of chess. Level one is perfect for beginners. Level six is a real challenge for any Soviet Chess Champion.

LIKE PLAYING KARPOV The system is the perfect way to sharpen

your chess skills. It not only has six different skill levels, but if you are playing against the computer at level two and you are beating it, you can switch the unit to level six. It's like having Karpov as your new opponent-right during mid game.

To play against the computer, you enter your move on the unit's keyboard. You then wait until the computer examines all its options and selects its move. You then move the computer's chess piece to correspond with its request as shown on the display. A board layout is provided to show you where each chess piece should be moved.

The JS&A Chess Computer is programmed for such complex functions as castling, pawn promotion and enpessant. It also allows you to start in midgame, setting up any situation you choose. This is perfect for those players who wish to examine particularly intricate problems and allows for an infinite number of game variations.

SHARPEN SKILLS If you already play chess, the JS&A unit

provides a new chess dimension. If you haven't played chess, the system is a good way to learn and sharpen your skills.

The JS&A Chess Computer measures only 21/e"x 47/e"x 87J8" and weighs just a few ounces, so if service is ever required you can slip it in its handy mailer and send it back to our prompt service -by -mail center. Service should never be required, but it is reassuring to know that service is an important consideration in this program.

JS&A is America's largest single source of space-age products-further assurance that

your modest investment is well protected. We suggest you order a JS&A Chess

Computer and use it for 30 days. Play against it. Raise or lower the level as you play and watch how the computer's personality can change right in mid game-from a tough competitor to a push over.

Test our level six and see if you'd -have much of a chance against the Soviet Champion Karpov. Then, after you've really given it a workout, decide if you want to keep it. If not, you may return your unit within our 30 day trial period for a prompt and courteous refund, including your $2.50 postage and handling charge. There is no risk. Each JS&A Chess Computer comes complete with instructions and an AC adapter (no batteries are required).

To order our JS&A Chess Computer, send your check for $99.95 plus $2:50 for postage and handling (Illinois residents please add 5% sales tax) to the address below or credit card buyers may call our toll -free number below.

Karpov told us (and this is a direct quote) "I have played all the rest of the American chess computers and find that the JS&A unit is the best value for the dollar. I will accept an offer to endorse the game, however, you can forget about your $50,000 offer and spend the money on advertising to spread the word."

Thank you, Mr. Karpov. We appreciate your honesty and your generosity and we promise to spread the word.

And you can help us America. Order a JS&A Chess Computer at no obligation, today.

PRODUCTS

O ® THINK®

Dept. PE One JS&A Plaza Northbrook, III. 60062 (312) 564-7000

Call TOLL -FREE 800 323-6400 In Illinois Call (312) 564-7000

©JS&A Group, lnc.,1979


ow to Ge 1 places at once,

locically.

When's the last time you had a nice chat with an integrated circuit? All you need is something to translate what's happening in its simple little logical mind. Something like our popular Logic Monitors.

Clip one onto an IC-any DIP up to 16 pins-and the 16 LEDs atop our Logic Monitor flash to the rhythm of the state of each pin. You have, in effect, 16 tiny logic probes in one pocket-size circuit -powered

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CSC for yourself!

CONTINENTAL SPECIALTIES CORPORATION Corporate Headquarters:

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351 California St., San Francisco, CA 94104 (415) 421-8872, TWX 910-372-7992

Canada: Len Finkler Ltd., Ontario

EUROPE, AFRICA, MIDEAST: CSC UK LTD. Shire Hill Industrial Estate Units 1 and 2 Saffron Walden, Essex CB 11 3AQ

- Telephone Number: SAFFRON WALDEN 21682 TLX 817477

®Copyright 1979 Continental Specialties Corporation,

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800-243-6077 CIRCLE NO. 12 ON FREE INFORMATION CARD

*Manufacturer's suggested U.S. resale. Prices, specifications subject to change without notice.

POPULAR ELECTRONICS


APRIL 1979

VOLUME 15, NUMBER 4

About the cover: The "True RMS" Voltmeter

featured here will at

last enable readers to

measure "effective" voltages of odd -shaped

waveforms without spending considerable monies.

Cover Art by George Kelvin

JOSEPH E. MESICS Publisher

ARTHUR P. SALSBERG Editorial Director

LESLIE SOLOMON Technical Director

JOHN J. McVEIGN TecJunc! Editor

JOHN R. RIGGS Managing Editor

HAROLD A. RODGERS Senior Editor

ALEXANDER W. BURAWA Features Editor

EDWARD I. BUXBAUM Art Director

ANDRE DUZANT Technical Illustrator

CARMEN VELAZQUEZ Production Editor

RUTH POLSKY Editorial Assistant

Contributing Editors Hal Chamberlin, Lou Garner, Glenn Hauser Julian Hirsch, Ralph Hodges, Forrest Mims

JEFF NEWMAN Assistant to the Editor

LINDA BLUM Adoertising Service Manager

MARIE MAESTRI Executive Assistant

Po?IIIar Elect onics® WORLD'S LARGEST -SELLING ELECTRONICS MAGAZINE

Feature Articles DESIGN OF TRANSMISSION -LINE TRANSFORMERS/ Roy Hartkopf 47

How coreless transformers can be made from coaxial transmission lines.

MICROCOMPUTER I/O BOARD BUYING DIRECTORY/ Staff 68 ENGLISH BROADCASTS AUDIBLE IN NO. AMERICA/ Glenn Hauser 82

Construction Articles BUILD A TRUE RMS VOLTMETER/ Daniel Metzger 35

Measures effective ac voltage rather than the usual average values.

BUILD A DYNAMIC AUDIO NOISE FILTER/ Colleen McNeice and Roger Cofa 51 Cleans up radio. tape and record signals from any stereo system.

THE MORSE -A -WORD, Part Two: CONSTRUCTION, ALIGNMENT AND USE/ George Steber_j7 Conclusion describes how to assemble the main pc board and LED readout.

Columns STEREO SCENE/ Ralph Hodges 13

The Automation of Tape.

EXPERIMENTER'S CORNER/ Forrest M. Mims 76 Analog Sample/Hold Circuit.

COMPUTER BITS/ Leslie Solomon 86 Language Translation.

PROJECT OF THE MONTH/ Forrest M. Mims 93 Experimental Solid -State Oscilloscope.

Julian kirsch Audio Reports KENWOOD MODEL KT -917 FM TUNER 20 REALISTIC SCT-30 STEREO CASSETTE DECK 29 DENON DP -2500 RECORD PLAYER 32

Departments r _

EDITORIAL/ Art Salsberg 4 19791/2

LETTERS 6 NEW PRODUCTS 9 NEW LITERATURE 12 SOFTWARE SOURCES 92 OPERATION ASSIST 105 ADVERTISERS INDEX 115

EDGAR W. HOPPER Publishing Director

APRIL 1979 3


Popular Electronics ZIFF-DAVIS PUBLISHING COMPANY

Editorial and Executive Offices

One Park Avenue, New York. New York 10016

212-725-3500 Joseph E. Mesics (725-3568)

John J. Corton (725-3578) Bonnie B. Kaiser (725-3580)

Midwestern Office Suite 1400, 180 N. Michigan Ave.. Chicago. IL 60601 (312-346-2600)

Midwest Representative: Buzz Vincent

Western Office 9025 Wilshire Boulevard. Beverly Hills. CA 90211

213-273-8050: BRadshaw 2-1161

Western Representative: Norm Schindler Suite 205. 20121 Ventura Blvd.,

Woodland Hills. CA 91364 (213-999-1414)

Japan: James Yagi. Oji Palace Aoyama: 6-25. Minami Aoyama, 6 Chame. Minato-Ku,

Tokyo, 407-1930/6821. 582-2851

ZIFF-DAVIS PUBLISHING COMPANY Philip B. Korsant. President

Furman Hebb. Executive Vice President Phillip T. Heffernan, Sr. Vice President Edward D. Muhlfeld. Sr. Vice President

Philip Sine. Sr. Vice President. Secretary Lawrence Sporn. Sr. Vice President, Circulation and Marketing

Baird Davis. Vice President. Production George Morrissey, Vice President Sydney H. Rogers, Vice President

Sidney Holtz. Vice President Albert S. Traina. Vice President Paul H. Chook. Vice President

Edgar W. Hopper. Vice President Robert N. Bavier. Jr.. Vice President

Selwyn Taubman, Treasurer

W. Bradford Briggs. Vice Chairman

ZIFF CORPORATION William Ziff. Chairman

I. Martin Pompadur, President Hershel B. Sarbin, Executive Vice President

POPULAR ELECTRONICS. April 1979. Volume 15, Num- ber 4. Published monthly at One Park Avenue. New York. NY 10016. One year subscription rate for U.S. and Possessions. $13 00: Canada. $16.00: all other countries. $18.00 (cash orders only. payable in U.S. currency). Second Class postage paid at New York, NY and at additional mailing offices. Authorized as second class mail by the Post Office Depart- ment. Ottawa. Canada. and for payment of postage in cash.

POPULAR ELECTRONICS including ELECTRONICS WORLD, Trade Mark Registered. Indexed in the Reader's Guide to Periodical Literature.

COPYRIGHT 4 1979 BY ZIFF-DAVIS PUBLISHING COM- PANY. ALL RIGHTS RESERVED

Ziff -Davis also publishes Boating. Car and Driver. Cycle. Flying, Popular Photography, Skiing. Stereo Review, Elec- tronic Experimenter's Handbook. Tape Recording & Buying Guide, Stereo Directory & Buying Guide, and Communica- tions Handbook.

Material in this publication may not be reproduced in any form without permission. Requests for permission should be

directed to Jerry Schneider. Rights and Permissions. Ziff. Davis Publishing Co.. One Park Ave.. New York, NY 10016.

Editorial correspondence: POPULAR ELECTRONICS, 1

Park Ave.. New York, NY 10016. Editorial contributions must be accompanied by return postage and will be handled with reasonable care: however, publisher assumes no responsi- bility for return or safety of manuscripts. art work. or models.

Forms 3579 and all subscription correspondence: POP-

ULAR ELECTRONICS. Circulation Dept., P.O. Box 2774, Boulder. CO 80302. Please allow at least eight weeks for change of address. Include your old address, enclosing, if possible, an address label from a recent issue.

The publisher has no knowledge of any proprietary rights which will be violated by the making or using of any items disclosed in this issue.

MPA

Member Autl,t Bureau or C,rculatio.ss

4

Editorial 1979th

The Consumer Electronics Show in Las Vegas this past January revealed what we can expect to be sold in stores during the first half or two thirds of '79. In most cases, products will remain the same as '78 year-end models, judging from what we saw at this giant trade convention. There were exceptions, though, as follows.

At the Jockey Club Hotel, away from the Convention Center mainstream, about 100 smaller audio companies were gathered in hotel suites to display their products. With late and limited publicity as to the existence of this added location, and owing to abominable elevator service, it was a challenge to cover it. But the effort was worthwhile, for here is where one can generally find the design innovator/ entrepreneur person and, consequently, learn how a product really works. At one such meeting, I previewed a preamp with an audio hologram function, plus a 200 W/ch "Magnetic Field" power amp housed in a 63/4" -cube chassis, weighing about 12 lb., and tentatively priced at 75C per channel -watt. (We'll have a full test report on the prototype Carver Corp. preamp next month.)

At the main show, spread out over some 459,300 sq. ft., personal computer exhibits were clearly in evidence, Ohio Scientific, Apple, APF, and Commodore PET, among them. Bally introduced a new computer language called "Graffix" for expanded functions, while Mattel (yes, the "toy company") debuted its "Intellivision" system. The latter is a programmable game component which is expanded to a "computer" with a mating 64 -key keyboard component. Uses prerecorded tapes.

Microprocessors were used for more dedicated applications, of course. For example, Coleco Industries (another "toy company") introduced its ZODIACTM as- trology computer; Comus, its hand-held "C-6 Diet Computer" for computing proper caloric needs according to input information on weight, height, type of exercise, etc. And then we saw-and tried out-Craig's portable M1 00 Language Transla- tor. It converts English to another language automatically, with the foreign language reading out on a blue Digitron display. Memory capsules ($25 each) include Spanish, French, Italian, German and Japanese at this time, each with a vocabulary of about 1,500 words. Talking computerized chess games from Boris and Fi- delity Electronics astounded many attendees, and for you Contract Bridge and/or Backgammon enthusiasts, there were computer -opponent games exhibited. Tex- as Instruments' programmable TI 58 and 59 solid-state software libraries im- pressed me, too.

The car stereo rage was certainly carried over into the CES, with numerous models shown. With one, you can now feel the sound as well as hear it owing to a "Bodysonic" amp that makes a seat cushion pulsate as music is played. It's from Pioneer Electronics of America. And from Fosgate is a four -channel 4 x 50W car amp that uses the Tate system.

We listened to a digital audio disc system developed by Matsushita Electric (sounded great!); marketing plans are incomplete, however. And also liked one of the least expensive items at the show, a Discwasher "Hi -Fi Seer" audio illuminator; a small, $7 flashlight -mirror system with on -off switch that lights up those dark re- cesses in a hi-fi cabinet.

In the communications field, Nevcom's cordless CM -100 communications microphone, with a three -meter range, worked beautifully. JS&A is marketing it. And writing about cordless, a handful of cordless telephone handsets were exhibited at the show. One of them, Pathcom's "EZ Phone," startled me when an incoming call caused it to ring while in the jacket pocket of the person I was talking to. It operates at 1.6 to 1.8 MHz and 49.8 to 49.9 MHz under Part 15 of the FCC Rules (no license required). About $170.

Among other interesting products revealed at the show were: "FlexSwitch," a thin, pressure -sensitive membrane that's designed to interface with logic circuitry. A prototype designer's kit costs $10 (Sheldahl, Electrical Products Div., Northfield, MN 55057.) Another was a portable synthesizer from England, the Tylophone 350-S, that simulates sounds of more than 20 different instruments when sliding a stylus across a 31/2 -octave keyboard.

With about 811 exhibitors in all, space doesn't permit me to mention all the newly introduced products. But as you can see, 19791/ will be an interesting part -year.

POPULAR ELECTRONICS


Here it is at last... THE FIRST FLOPPY DISK BASED COMPUTER

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The Challenger 1P Mini -disk system features Ohio Scientific's ultra -fast BASIC -in -ROM, full graphics display capability and a large library of instant loading personal applications software on mini -floppies including programs for entertainment, education, personal finance, small business and now home control!

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The Cl P MF configuration is very powerful. However, to meet your growth needs it can be directly expanded to 32K static RAM and a second floppy by simply plugging these options in. It

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The cassette based Challenger 1P offers the same great features of the mini -disk system including a large software library except it has 4K RAM and conservative program retrieval time. Once familiar with personal computers, you'll be anxious to expand your system to the more powerful C113 MF.

You can move up to mini -disk performance at any time by adding more memory and the disk drive. Contact your local Ohio Scientific dealer or the factory today.

* Both systems require a video monitor, modified TV or RF

converter and home television for operation. Ohio Scientific offers the AC -3 combination 12" black and white TV/monitor for use with either system at $115.00 retail.

All prices, suggested retail.

OHIO OIENTIFIG 1333 S. CHILLICOTHE RD., AURORA, OHIO 44202 (216) 562-3101

CIRCLE NO. 44 ON FREE INFORMATION CARD


Announcing four tiny advances with

room -filling benefits!

fir

New 57-IIBATIO stylus with 1. minimum mass and 2. improved contour

3. New low -mass magnet assembly

In the tiny world of the stereo cartridge, microscopic differences in dimensions are all-important. Which is why the extremely low moving mass of the new AT15SS is a major achievement in stereo technology.

For instance, to the best of our knowledge our new stylus is the smallest whole diamond used in series production. In cross-section, it's 36% smaller than our best previous model. It is also nude - mounted to further reduce mass at the record surface. And the square -shank design insures exact alignment with groove modulations.

All this is so small you'll need a microscope like the one above used by many A -T dealers to.see the details. If you look very closely you'll also see we've slightly revised the contour of the Shibata tip. The combination of minimum mass and new contour which we call Shibata+ offers outstanding stereo reproduction, especially of the latest high level recordings.

But there's more. Extremely low distortion results from a new ultra -rigid

4.New Beryllium r.antitever

Beryllium cantilever which transmits stylus movement without flexing. And flatter response plus better tracking is achieved by a new method of mounting our tiny Dual Magnets to further minimize moving mass.

Four tiny differences, yes. But listen to the new AT15SS or the hand -selected AT2OSS for ultra -critical listening. You'll find out that less IS more. At your Audio-Technica dealer now. Note: If you own a current ATI5Sa or AT2OSLa, you can simply replace your present stylus assembly with a new' SS" stylus assembly to bring your phono system up to date.

"1",w11---9"." Model AT15SS Model AT2OSS

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q

Letters AUTOMATIC KEYER FOR HAMS

After reading "Control Your Model Railroad With Audio Tape" (November 1978), I

thought of another very practical use for the project. It can be used as a keypr for prerecorded Amateur Radio messages with a ham rig equipped with full break-in capability. The keyer could be used to send a CO message with perhaps a 20- or 30 -second delay before the message is repeated. The conversion is simple: connect a keyer in place of S3 and forget S4 altogether and use the contacts of K1 to key the transmitter. -Brian Torr, Monte Rio, CA.

DISCO MIXER SPECIFICATIONS

For thosé who are interested, here are the frequency -response and distortion specifications for my "Disco Preamp/Mixer" (Septem- ber 1978). Phono Section: input impedance, 47,000 ohms and 100 picofarads; input overload 60 millivolts at 1 kHz; playback equalization, IEC ± 0.5 dB; input sensitivity, 4 mV at 1

kHz (for 500 mV output); S/N referred to 5 mV, 87 dB (IHF "A" weighting); THD + N, 0.1% (1 kHz at rated output); IM (SMPTE), 0.09%. High Level: input impedance, 50,000 ohms; frequency response, PA only, -0.4 dB at 20 Hz, 0 dB at 100 kHz, DM, -1 dB at 20 Hz, 0 dB at 100 kHz; IM (SMPTE), PA & DM, 0.003%; THD + N: (at 8 V rms) 20 Hz -0.012%, 2 kHz -0.0018%, 10kHz- 0.0035%, 20 kHz -0.0052%; output clipping, 9 V rms; output noise, 92 dB below 500 mV (IHF "A" weighting) (117 dB below clipping).-John R. Roberts.

CIRCUIT CHANGE REQUEST

"Build a Digital Darkroom Timer" (August 1978) is really a lifesaver, but I have a request to make regarding its design. Would it be possible to change the circuitry so that the desired exposure time can be entered into the timer via a keypad?-Freddie T. Reitz, Waupun, WI.

We often receive letters in which readers ask us to detail how to make modifications to our published projects. Our response to such requests must be that we do not have the re- quested information and any attempt to provide this information requires researching that would jeopardize our deadlines.-Ed.

POPULAR ELECTRONICS


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1

1 1

1

ELECTRONICS BOOK CLUB Blue Ridge Summit, Pa. 17214 Please open my Trial Membership in ELECTRONICS

BOOK CLUB and send my copy of "THE POWER

SUPPLY HANDBOOK" ABSOLUTELY FREE! If not

delighted, I may return the book within 10 days

and have my Trial Membership cancelled. I agree

to purchase at least four books during the next 12

months, after which I may cancel my Membership

at any time.

Name Phone

Address

City

State (Valid for new Members only.)

Zip PE -49

APRIL 1979 CIRCLE NO. 18 ON FREE INFORMATION CARD


CI rjo

Forty-nine out of 50 executives surveyed said they found it an absolute necessity - even though they bought it for convenience or on a lark. And most prefer it to having their secretaries or switchboard operators place their calls.

Rapidial will help make your day. Every day. Imagine dialing a number by touching a button. And, then, having the number you are calling ring in a second. (Tell somebody you will call right back, and his phone will ring the instant he hangs up!)

Works with any phone - One line or 10. Even turns a rotary into a Touch Tone®. F.C.C. approved, manufactured in the U.S. and guaranteed for one full year, Rapidial comes with a plug-in wall jack adapter (4 - prong or modular combination) for phones with one or two lines. For permanently installed .office phones with up to six lines we have an inexpensive, two -screw "sandwich connector". And for phones with up to 10 lines the phone company will install an RJ35X connection (for a one time charge of about $30).

Rapidial works on any line of any multiple line phone. It also works with rotary phones. In fact, you can use the Rapidial keyboard to place all your calls with Touch Tone speed and ease. It's Hands -Free Rotary or Touch Tone, using the Rapidial keyboard regularly has added advantages. First, it's hands free telephoning. With a built- in type speaker system. You lift the receiver only when you hear someone answer. Sec- ond, if the line processed is busy, Rapidial shuts itself off automatically, remembering the number so you can redial at the touch of a button-as often as necessary.

There is no call you can't make. What's more, every call-local, long distance, inter- office, even over seas, is easier and faster. With Rapidial you can store as few or as many as 10 digits (area code and number) in memory. If you have to dial "9" or "1" or both, need the operator, want to access a WATTS line or a PABX system, just touch the extra buttons you need plus the button with the number you're calling. Bonus Features About the size of a hand-held calculator, Rap- idial sits neatly on your desk next to your telephone. Always ready with no off/on switch to worry about. The numbers in memory are identified on the panel on top. The lower section is the Touch Tone keyboard pad. An LED DISPLAY lets you check any number in memory. The PAUSE CONTROL sets the machine to wait for a dial tone. There's an

Oe Touch Tone is a mark of A. T. & T. Co.

AutOmatic : .

\ITransmigsion. , 0.0000

li'000e0 000400 00000 ;DáN mo.o} w

6

NM, OR. ! 9

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AUTOMATIC CANCEL button if you change your mind or hit the wrong number. And the BATTERY BACKUP protects the memory in a power failure.

Five Different Uses For peak operation and maximum efficiency at the lowest cost, Rapidial stores 20 numbers in memory-eliminating wrong numbers and having to stop to look them up. Numbers entered in seconds and changed-any time -by Rapidialing the new number.

Basically it allows you to place frequently made calls yourself in an instant. In far less time, actually, than it would take you to tell your secretary to do it for you. With immediate access to emergency numbers.

Interestingly, our survey unearthed some rather surprising and highly enterprising additional uses.

For example, most executives store both their most frequently called numbers, family, friends, clients or customers, service organi- zations and suppliers...and those important but less frequently called numbers that almost always have to be looked up.

Others use Rapidial mostly for inter -office calls. Since remembering extensions is almost impossible. And it's kind of inconsider- ate to have a man get on the phone with your secretary first all the time.

The Memo Caller-or daily telephone or- ganizer-is one of the more intriguing uses we discovered. These men (or their secretaries) program each day's calls. Crossing off the ones that are completed (adding new

-

4

Who else wants to save time, trouble and, aggravation? At $99, Rapidial" is America's lowest priced,, best selling automatic dialer.

ones as necessary). A glance assures you no one's been left out, no call back has been forgotten. And a touch of the button gets you the next man on your list.

Finally, many report leaving the bottom bank of storage cells blank. Reserving them for the flow of calls that always accompanies a special deal or negotiation.

$20 Less Than Retail ... $50 Less Than The Closest Competitor's. A repetory-or automatic dialer-from the phone company with 15 numbers costs $105 to install and $9 a month plus tax to lease- forever. For $130 you can get a 16 number dialer-with no keyboard of its own so it's only good for those numbers stored in memory. For $149.95 you can get a 20 number unit- but it's primarily for the home since a special telephone company installation for any multiple line phone is needed and it's not recommended at all for phones with more than three lines.

Rapidial will sell in stores for $119.95. But is being introduced by mail for $20 less. Why? To get as many as possible in use now by the kind of people Douglas Dunhill reaches by advertising in America's most influential publication.

So, you can have the easiest to use, most efficient and versatile unit on the market today for less than anybody else. And without risking one cent!

30 Day Trial If your Rapidial isn't the executive necessity we described, the home convenience you hoped for, just return it in 30 days for a full refund. And we'll thank you for trying.

The price, including backup batteries and adapter for your wall jack, is just $99.00 plus $2.50 shipping and handling. The Amphenol connection for multiple line office phones is only $19.95 extra. The adapter for the RJ35X is $19.95. (For the RJ35X connection itself, for phones with six or 10 lines, call your telephone business office.)

Deduct 10% from the price of the Rapidial on orders for ten or more. Call toll free to charge to your national credit card or send your check to Douglas Dunhill. (Illinois residents add sales tax.) You'll find it a far cry from standard transmission.

CALL 800-621-5554 Illinois residents call 800-972-5858

Douy/alDuuhi// Inc. AFFORORB4.E OURUTY Dept. 74-2339 Ten Douglas Dunhill Drive, Oak Forest, IL 60452 © Douglas Dunhill Inc. 1979


a POPULAR ELECTRONICS


New Products Additional information on new products covered in this section is available from the manufacturers. Either circle the item's code number on the Free Information Card or write to the manufacturer at the

address given.

Sanyo Biamplified Auto Sound The Sanyo Model FT -1490A is a car in -

dash AM/FM/cassette system with biamplification. Its tuner has a dual -gate MOS- FET front end, PLL multiplex decoder,

1-p.V FM sensitivity (mono), and 30 - to -16,000 -Hz response; Dolby noise re-

duction for FM and tape; loudness contour control; selectable standard/biamplification mode; and tape transport with full au- to -reverse and auto -repeat, self -draw tape compartment, and locking fast -forward and rewind. Biamplification provides separate amplifiers for bass (rated 12 watts/channel) and treble (2 watts/channel). $199.95. CIRCLE NO. 86 ON FREE INFORMATION CARD

require fewer mechanical and electrical connections and fewer resistive contacts between loading coil and cable termina- tions. Persuaders are tested at 500 watts of power and rated at 1000 watts continuous. Magnetic mounts are tested at 55

mph. The active radiator element is a 60" (1.5-m) long tapered stainless steel whip. Mounted on the center of a car roof, SWR is claimed to be 1.5:1 or less across all 40

CB channels. A choice of magnetic or trunk -lip mount is available, and mounts come in silver, bronze, black, blue, red, white, and clear. $34.98.


electret element has a rated 30 -to - 18,000 -Hz (no reference given) frequency range. The receiver has a standard phono plug output for connection to a PA or other microphone input and a VU meter to monitor the audio output signal level of the transmitter. A single 9 -volt battery is required in the transmitter and the receiver. $69.95.

CIRCLE NO. 89 ON FREE INFORMAL ION CARD

Antenna Inc. Low -Profile CB Antennas The PersuaderTM is a new line of CB antennas from Antenna Inc. It features a pre -

tuned hand -wound loading coil located right in the mounting cup instead of the usual nontunable and low -power printed - circuit assembly generally used in low -

profile antennas. This design is reported to

i

Realistic High -Power Receiver The Realistic Model STA-2100 is said to

be the most powerful AM/FM stereo re-

ceiver ever offered by Radio Shack. It is

rated at 120 W/channel minimum rms at 8

ohms from 20 to 20,000 Hz with no more than 0.1% THD. Special features include separate bass, treble, and midrange tone controls, with selectable crossover points on bass and treble; switchable 25- and 75- µs deemphasis for FM Dolby reception; a

multiplex filter, AM signal strength and FM

center -channel meters; and dual power meters. Both DIN and phono-type input

-- _ - ., }

-- c c-t+11 t rs

and output jacks are provided for use with two tape decks. (One can record from one source while listening to another.) Specifi- cations: 15 to 25,000 Hz ± 2 dB at 10 watts frequency response; 0.05% IM distortion at 70 watts; 70 -dB phono, 75 -dB AUX S/N; 1.6-µV (10.1-dBf) FM sensitivity; 75 dB alternate -channel separation; 52 dB at 1000 Hz FM stereo separation; 0.1% stereo, 0.05% mono FM THD. $599.95


Hickok Hand -Held DMM Features LCD Display The 31/2 -digit pocket-size Model LX -303 DMM from Hickok 'Electrical Instrument Co. features a liquid -crystal display for long battery life. Numeric display of the pa -

rameter being measured is backed up by

automatic polarity and overrange indication. The instrument can measure from 0.1

mV to 1000 V (±0.5% of reading ±0.5% full-scale) on dc; from 0.1 V to 600 V (-±1%

of reading ±0.5% f.s.) on ac; 0.01 nA to 200 mA (±1% of reading ±0.5% f.s.) on

dc; and 0.1 ohm to 20 megohms (±0.5% of reading ±0.5% f.s.). Protection is provided to 1000 volts on all dc ranges except the 200 -mV range, where ít is to 500 V; to 600 V on all ac ranges; and to 120 V on all re-

sistance ranges. $74.95.


Mura Wireless Microphone The Mura Model WMS-49 is a high -power wireless microphone system that contains a matched transmitter and receiver, both of

which are crystal controlled. The system operates in the 49 -MHz walkie-talkie band where 100-mW output power is permitted without an FCC license. The microphone's

ReVox Direct -Drive Turntable with Tangential Tracking The B790 turntable from ReVox has no

tonearm in the usual sense, but is

equipped instead with an optoelectronic servo mechanism to position the cartridge.

APRIL 1979 9


ALL NEW AND ADVANCED DMM by Sabtronics

for only $89.50

i!1 n 0-r . t - it

. 200 2R 211

1 DC - 200m 20m 2A

n AL AC A y 20001 20 1 _...

The new and advanced Sabtronics Model 2010A is absolutely amazing .. . it gives you more performance, features and accuracy at a price no other Digital M alti- meter can approach. It is versatile and rugged, for bench and portable use, with laboratory standard accuracy.

Greater Long -Term Accuracy State -of -the -Art design features include a laser -trimmed decade resistor network and an ultra -stable band -gap reference element to insure long-term accuracy. Basic DCV and Ohms accuracy is 0.1% ±1 Digit, guaranteed for one year. With 31 ranges and 6 functions you can measure AC and DC volts from 100 µV to 1000V; AC and DC current from 0.1µA to 10 A; resistance from 0.1oto20Ma

Unique X10 Multiplier Switch This exclusive feature of the Model 201 OA gives you a convenient means of selecting the next higher decade range. The Hi -Lo Power Ohms capability gives you three High -ohm ranges that supply enough voltage to turn on a silicon junction for diode or transistor testing. Measure in -circuit component resistance with three Low -ohm ranges.

Touch and Hold Capability The optional touch and hold probe allows you to make measurements in hard -to - reach places without taking your eyes off the probe tip. A button on the probe retains the display reading after the probe tip is removed from the test point.

5_515.

VS1mA COMMON 10A MAX

_( '1 r11 ItY 500V.

IDOmA MAX

MAX á

sabtronics p MODEL 2010A DIGITAL MUITIMETER

Other Important Features This quality instrument includes an ACV Frequency Response of 40 Hz to 40 kHz, automatic polarity, automatic zero, automatic decimal point, overrange indication, and overload protection on all functions and ranges. The bright LED display gives readings to ±1999 and is easy to read in dim light or bright light.

Reliability and Performance at Low Cost The Model 2010A is factory tested, calibrated and is supplied complete with test leads, probes and detailed operating manual. A full compliment of optional accessories is available to increase the versatility of your 2010A DMM. Because you buy factory direct, you get this high - quality, full performance instrument at an incredibly low price of only $89.50.

Designed and made In U.S.A.

Brief Specifications DC Volts: 100µV to 1000V in 5 ranges AC Volts: 100µV to 1000V in 5 ranges DC Current: 0.1µA to 10 A in 6 ranges AC Current: 0.1µA to 10 A in 6 ranges Resistance: 0.10 to 20 Mtt in 6 ranges Diode Test Current: 0.11,A, 10µA. 1 mA ACV Frequency Response: 40Hz to 40kHz Input Impedance: 10 MO on ACV and DCV Overload Protection: 1200 VDC or RMS on all voltage ranges except 250 VDC or RMS on 100mV and 1 V AC ranges. Fuse protected on ohms and mA ranges. Power Requirement: 4.5 to 6.5 VDC (4 "C"cells) optional NiCd batteries or AC adapter/charger Display: 0.36" (9.2mm) Digits reading to ±1999 Size: 8"W x 6.5"D x 3"H (203 x 165 x 76 mm) Weight: 1.5 lbs. (0.68kg.) excl. battery

(Batteries not included)

Orders Yours Today Call us with your Mastercharge or Vida order or use the convenient order form to take advantage of this special introductory offer.

Making Performance Affordable sabtronics 13426 Floyd Circle WS 24 Dallas. Texas 75243

Telephone 214/763-0994

To: Sabtronics International, Inc., 13426 Floyd Circle M/S 24, Dallas, TX 75243 PLEASE SEND ME THE FOLLOWING:

Model 2010A Digital Multimeter(s) @589.50 $

AC Adapter/Charger(s) @5 7 50 S

Nickel -Cadmium Battery sets @517.00 S

Touch -and Hold Probes @$18.00 S

For delivery in Texas, add Sales Tax $

Shipping, Handling and Insurance per unit $4.00- $

Check enclosed Money Order, or bill my Master Charge Visa TOTAL $

Account No. Expiry Date Name

Street

City State Zip *Continental U.S. only. AK, HI & PR, $5.00. Canada: 56.50. Foreign: S19.00 Airmail. PE -4

ti

10 POPULAR ELECTRONICS


The platter is turned by a direct -drive servo motor with quartz -crystal speed control at

331/2 or 45 rpm with speed adjustments of

±7% and a four -digit, seven -segment LED speed readout. The cartridge is carried by

a mounting plate of aluminum 4 cm long

and weighing a little over a gram. The arm/ cartridge assembly is mounted on an over- head carrier mechanism that moves the

cartridge tangentially across the face of the record on steel rails. Lateral movement is

controlled by a sensing system using an

LED light source that advances the car-

tridge at the groove rate. The company claims that this arrangement eliminates tracking error and noncompliance due to

the effective moving mass of a tonearm. The system is supplied with an Ortofon M20E moving -coil cartridge and a brush that automatically cleans the sylus be-

tween records. $799.


and data inquiry in a microcomputer sys-

tem. It features separate numeric keys.

The new Model 1410 economy computer terminal is based on the company's 1400

and 1500 video terminals. It operates with

a standard EIA RS -232 interface with eight transmission rates (selectable onboard) up

to 9600 baud to accommodate all 128

ASCII character codes. A cooling fan is not

required and electronic components are

mounted on a single printed -circuit board.

CIRCLE NO.94 ON FREE INFORMATION CARD

CPI CB AM/SSB Mobile The Model CP-2500 mobile AM/SSB CB radio system from Communications Pow- er, Inc., (CPI) combines the security of a

trunk -mounted transceiver module with the

i

convenience of a dashboard control console. The system's control unit includes a

numeric channel display; upper/lower- sideband and AM selector; volume, PA

provision, r -f gain, microphone gain, clarifi- er, and squelch controls. The receiver features a separate, switchable automatic noise limiter and blanker; a logarithmic speech compressor; and front -panel signal strength, transmitter power and modulation meter. An 18' (5.5.-m) cable is provided for interconnecting the control and transceiver units.


Nikko Compact Preamplifier Nikko has added the ultrathin (2 3/32"H) Beta III PET preamplifier to its professional series of audio components. It uses newly designed FETs throughout its signal circuitry for fast and accurate signal reaction, high S/N characteristics, and extremely

low distortion. Its specifications include: within ±0.2 dB for the 30 -to -15,000 -Hz RIAA phono frequency response (10 to 50,000 Hz ±0.5 dB tuner and Aux); less than 0.004% THD phono at 3 volts tape out (0.005% THD tuner and Aux at 2 volts preamp out); 2 mV phono (110 mV all other) input sensitivity; selectable 22k/47k/100k phono (47k all other) input impedance; 81 dB phono (at 2 mV input), 100 dB tuner and AUX S/N; ±10 -dB bass and treble tone -control range; 350 -mV maximum phono input; 1 -volt output 1 and 2 and 100 -mV tape 1 and 2 output level; 100 ohms output 1 and 2, 2200 ohms tape 1 and 2 output impedance; 19'W x 13"D x 2 3/32"H (48.3 x 33 x 5.3 cm); 13 lb (5.9 kg). $399.

CIRCL F NO 950N FREE INFORMATION CARD

ton frequency entry. Frequencies being monitored appear in a lighted numeric display. Up to 20 frequencies can be in any sequence or mix of bands. A priority function alerts the user when a call is received on the priority frequency programmed into

the channel -1 location. Channels can be

activated in banks of 10, permitting a sin-

gle button to call up a group of 10 channels. Also, three search operations are

provided to locate active frequencies. Oth- er features include selective scan delay, scan speed selection, ac and dc operation, direct access to a programmed channel, and automatic and manual squelch.

CIRCLE NO 96 ON FREE INFORMATION CARD

Hazeltine Video Computer Terminal Hazeltine Corp. has introduced a new low- priced B&W video terminal for data entry

rwenne . ---

Electra Scanner Includes AM Aircraft Band Electra Company's "Bearcat 220" is

claimed to be the world's first scanning re-

ceiver to offer both standard FM Public

Ii=tenlos

Service Band (five vhf -uhf) and AM Aircraft Band reception in a single unit. The crystal -less ac/dc receiver employs pushbut-

MXR Flanger/Doubler The A4XR Flanger/Doubler produces a

wide variety of time -delay effects and is in-

stantly switchable between modes. Time

delay is 0.25 to 5 ms in the flanging and

17.5 to 70 ms in the doubling modes. Fea- tured are manual control over the delay time; mix control (between dry and un-

delayed signals); sweep controls for width

and speed; and regeneration control for added intensity. Many varieties of flanging, hard reverberation, and numerous types of doubling, which include subtle chorus effects, can be produced. The device is rack -

mountable and features instrument level inputs and outputs as well as line level in-

puts and outputs. Voltage -control terminals provide a means for externally controlling the delay and for ganging two units for stereo operation. $425.


Nihon Nav/Com Receiver Nihons COMNI R-1010 is a low-priced version of professional navigation/com-

' ^`

APRIL 1979 (Continued on page 12)


NEW PRODUCTS (Continued from page 11)

municatiori vhf AM air -band receivers. Fre- quency control is by a PLL frequency synthesizer that tunes across the entire 108- to -135.975 -MHz band in 25 -kHz steps. Tuning is accomplished with concentric kHz and MHz channel -selector knobs. A five -digit LED numeric display provides frequency readout. Other features include a squelch control and a front -panel headphone jack.

Hz ±3 dB on -axis; response drops 3 dB at

15 kHz 90° off axis, and at 10 kHz 1800 off axis. Nominal impedance is 4 ohms. Pow - er requirements are 30 watts rms (15 dBW) minimum, 500 W (27 dBW) peak maximum, 100 W (20 dBW) average. Height is 41%", and the system slopes from 161/4" square at the bottom to 8112"

square at the top. $575 each.



TRS-80 Microcomputer Epicure "Trilogy" Serial I/O Speaker System Electronic Systems has introduced a new

With its first three-way speaker system, the accessory for the Radio Shack Model

Model 3.0 "Trilogy", Epicure joins the TRS-80 microcomputer-an RS -232 com-

growing number of manufacturers with en- patible serial I/O that can be used with or

closures that avoid the conventional box without the expansion bus. On -board

shape. The Trilogy's truncated -pyramid design is claimed to reduce time delay and other sources of distortion, while increas-

switching is provided for 110, 150, 300, 600, 1200, and 2400 baud rates; odd, even, and no parity; five to eight data bits;

ing power -handling capacity. Its rounded and one or two stop bits. It is available

cabinet edges are said to eliminate diffrac- wired and tested as part number 8010C for

tion effects. The Trilogy's 10" woofer $79.95 or in kit form as part number 8010A

crosses over to its separately baffled 6" for $59.95. The etched and drilled printed

midrange at 400 Hz; midrange crosses circuit board is available separately as part

over to a 1" air -spring tweeter at 2600 Hz. number 8010 for $19.95.

Frequency response is rated at 32-20,000 CIRCLE NO. 100 ON FREE INFORMATION CARD

*Now Available In Kit Form. Here's your chance to build BORIS, widely regarded os the world's most advanced personal

Chess Computer. We hove received so many requests from Hobbiests and Kit Builders, that we're offering Him now, for the first time. in Kit form.

YOU DON'T HAVE TO BE AN ELECTRONIC EXPERT TO ASSEMBLE THIS ELECTRONIC MASTERPIECE!

BORIS comes ready to assemble, with easy, step by step instructions, moking this kit assembly o cinch for even the novice builder. Only the highest quality components ore used in this advanced microprocessor based computer, and each port has been tested to meet our rigid quality control standards.

BORIS is the perfect teacher and opponent. As o teacher, he'll suggest moves for you if you're uncertain of what to do next, or use his exclusive position programmer to set up practice games or remove pieces for handicapping.

NO OTHER PORTABLE CHESS COMPUTER PLAYS A STRONGER GAME! BORIS will keep you on your toes and make each game much more exciting by tolking to

you with messages flashed from his seemingly -human brain. BORIS will ploy at o level to teach a child, or let him loose, and he'll keep the attention of o Master.

We're only making a limited quantity ovoiloble, so act now!

You'll never find on easier kit to assemble or o more challenging finished product!

Complete Kit-$175.00. Thousands sold the world over for $300.00.

All computer parts included for you to enjoy this world famous Chess Com- puter. Also includes blueprints so you may build your own enclosure!

Handsome handcrafted Walnut Case shown in photo available for additional $30.00.

ORDER IMMEDIATELY AND WE'LL PAY FOR FREIGHT AND HANDLING!

Please send me DORIS Kit(s) ® $175.00 each. I enclose $ Check, Money Or- der or Credit Card Info., os payment with this order. Credit Card Acct. No. Expira- tion Dote (To receive my Handsome Walnut Case, I include on additional $30.00.) I understand that I may return the unassembled BORIS Kit within 10 days, if I am riot completely satisfied, and receive a full refund. NAME ADDRESS CITY STATE ZIP CHAFITZ, INC.. Deportment 750. 1055 First Street, Rockville, Maryland 20850.


12

New Literature

HEATHKIT 1979 WINTER CATALOG

A 96 -page catalog describes the latest electronic kits available from Heath Co. Areas of interest include color TV, hi-fi components, amateur radio, test instruments, digital clocks, personal computer systems, and other products for home improvement and family entertainment. New products include a rack - mounted FM/AM stereo tuner, a dc -to -35 - MHz dual -trace delayed -sweep oscilloscope, a portable rechargeable fluorescent light, a

solid-state heat/cool setback unit for home energy saving, a precision r -f generator, etc. Address: Dept. 470-170, Heath Co., Benton Harbor, MI 49022.

TRS-80 MICROCOMPUTER REFERENCE HANDBOOK

Radio Shack has published a 108 -page book for technically oriented persons with a good working knowledge of digital logic circuits and interest in the TRS-80 microcomputer. It in-

cludes technical information and schematic diagrams for both Level -I and Level -II TRS-80 systems. Topics include theory of

operation, adjustments and troubleshooting, the outside world (connections to external devices), parts list, etc. The Handbook is available for $9.95 from participating Radio Shack stores and dealers.

CHERRY KEYBOARD CATALOG

The 32 -page Cherry KBC-78 Keyboard Cata- log includes custom designed keyboards, a

keyboard designer's worksheet, solid-state or

gold crosspoint contact keyboards, a complete line of standard keyboards, keyboard switches and molded keycaps. The catalog features diagrams, photos and specifications. Address: Cherry Electrical Products Corpora- tion, P.O. Box 718, Waukegan, IL 60085.

INTRA-FAB EQUIPMENT CABINETS

An eight -page catalog from Intra-Fab de-

scribes its line of integrated cabinets specially suited to the needs of the computer hobbyist. Selection information is provided on the

construction, assembly, color and sizes of

enclosures including Mod -U -Box desktop ca-

binets, Mod -U -Line and Timberline equipment cabinets, and Mod -U -Rack modular electronic card rack system. Address: Intra- Fab, 660 Lenfest Rd., San Jose, CA 95133.

POPULAR ELECTRONICS


... 111 Stereo Scene THE AUTOMATION OF TAPE

AS RECENTLY as the 1960s, before cassettes were a factor in the serious recordist's life, there was Scotch 111

and then there were other tapes. Scotch 1 1 1 was a hoary old

product, with a history that descended linearly from the infan-

cy of tape recording in the U.S. Ampex then was trying to get this nation's very first tape recorders into reliable operation.

Not even the 3M Company, 111's creator and manufacturer, would argue that it was an outstandingly good tape. There were certainly products available affording much greater po-

tential performance when it was finally discontinued some

years ago. But for a long period it reigned as the standard tape-presumably because it was fairly consistent and widely available, and because it was the direct evolutionary heir to

the first U.S. ventures into magnetic recording. Tape recorders worldwide were adjusted to suit its characteristics, and when you were in doubt as to what tape to use for a particular application, you could almost always fall back on old 111 with

a reasonable expectation of getting the job done adequately. As much as anything else, it was the cassette era that

brought an end to Type 111 and its ilk. No longer was there the option of using a higher tape speed or a wider track width to get through the more demanding recording jobs. The format didn't allow such flexibility. And so it was the tape itself that had to improve, and it did-by leaps and bounds. But this progress was exacted at a certain price. Tapes necessarily drifted away from the electromagnetic characteristics of 111, at first gradually and then dramatically. In short order, cassette tape bore only a passing resemblance to its open -reel relatives in

terms of recording parameters, and then open -reel tapes be-

* u . -_----- - .-

JVC Model KD-A8 Cassette Deck

r-

, - `

s

-+ry +.

- - - - -

1 -- ía9Ú 1 '7'1

Hitachi Model D-5500 Cassette Deck

By Ralph Hodges

gan their own drive toward higher performance, bringing the relatively uncomplicated world of Scotch 111 to an end.

The Problematic Present. When a tape is improved in

any significant way-even if the change is something so os- tensibly physical as a smoother coating surface, with the magnetic particles themselves left unchanged-it behaves differ- ently with real -world tape machines as an electromagnetic en-

tity. Generally it requires (or at least would benefit from) a dif-

ferent level of recording -bias current, followed by the obligato- ry touch-up of the record equalization. These are adjustments that require good instruments and a certain amount of technical expertise to accomplish. And they are time-consuming. Buy a handful of tapes from your local retailer, just to find out which brand suits you best, and you may find that all of them require somewhat different bias and equalization, even if they

are of the same generic type. Optimizing your machine for

each one so that you can evaluate noise levels and other im-

portant performance criteria will prove to be a project of considerable proportions.

Then, when you have found your preferred tape and begin to buy it regularly, you will sooner or later come up against a

conundrum that isn't talked about much: batch variations. Tape manufacturer X's production run for June is not likely to

be identical to the product he offered in March. Very serious recordists buy in quantity from a single batch and resign themselves to readjusting their machines when their supply runs

out and a new batch must be investigated. Of course, all of this completely overlooks the plight of the

man on the street who cannot readjust his machine. He can

only hope that the bias and EQ switches on the deck have

enough flexibility to approximate the requirements of the tape. At the same time, he is going to be lured by ever -emerging new tapes claiming unprecedented levels of performance, but

completely undefined as far as his machine is concerned. Its

available bias and EQ characteristics may suit these tapes or they may not. He can only experiment and hope for the best,

or stick to the older product he's always used-not exactly a

formula for progress. The situation can only become more confused. Tape manu-

facturers routinely trade off one performance characteristic for

another they consider more desirable. It's a bit of a gamble, because if they stray too far from the mean characteristics exhibited by the majority of tapes of that generic type they risk missing the market. But at the same time it's a chance to fur-

ther the technology, and perhaps to open a new market.

Self-adjusting Decks. In short, tape -type accommodation is a dilemma that's been crying for a solution for years. And here it comes, or a good part of it, at least. Following closely on the heels of a few innovative cassette decks incorporating two-tone oscillators that enable you to achieve reasonably flat

APRIL 1979 13


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Addon MiniDisc for theTRS80*

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only from

$399W Requires 16K RAM, PERCOM DATA COMPANY, INC. Level II BASIC and Dept.PE 318 BARNES GARLAND, TEXAS 75042

Phone: (214) 272-3421 Expansion Interlace. To Order Call 1-800-527-1592

J

Dual and triple drives also available.

PEACOM

'RADIO SHACK ant TRS-80 are Iadernalks of Tandy Cottonton omen mat no Ielallonsmt to PERCOM DATA COMPANY. INC

CIRCLE NO.48 ON FREE INFORMATION CARD J

THE BIG PLUS + ° G raphic Equalizer

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Fully Assembled Plus Much, Much More! Absolutely equals or exceeds overall performance and features of any graphic equalizer made today!

AARON-GAVIN INSTRUMENTS, INC. 17231 Corla Avenue Tustin, California 92680

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assembled equalizers at $189.95, p.p.d. cabinet brochure

_unassembled equalizer kits at $99.95, p.p.d Horizontal (flat) E Vertical (up -right) California residents include 6% sales tax

Name

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Visa. & Muster Charge orders accepted

Dealer inquiries invited CIRCLE NO.1 ON FREE INFORMATION CARD

frequency response with virtually any tape (better than nothing, surely), has come a small wave of machines that contain (usually) 4 -bit microprocessors that undertake to set bias and equalization automatically through a pre-programmed test sequence. Last month I made reference to the Technics RS -1800, the first open -reel extravaganza (with a price to match, no doubt) that boasts this feature. But the man on the street is more Ikely to respond to the new cassette decks that will perform the same trick, best exemplified so far by the Hita- chi D-5500 and the JVC KD-A8.

Bias is the tricky consideration in this whole business, in large part because the optimum bias level for a tape is con- troversial. Depending on your criteria, you could adopt a bias level that: (1) maximizes output of the tape at some reference frequency (usually 1000 Hz); (2) minimizes third -harmonic distortion from the tape (for a test frequency of your choice, but often one in the vicinity of 1000 Hz); (3) minimizes modulation noise; (4) minimizes intermodulation distortion in any of a number of two-tone tests; or (5) satisfies any of a number of "ideal" criteria for the relative usable output levels from the tape at low and high frequencies.

Designers of self-adjusting tape decks have decided against incorporating distortion analyzers, the complexity and expense being a bit too much for today's market. Instead, they all aim for maximum output level (MOL) at some specific frequency. Full details are not available in every case, but the Hi- tachi machine can serve as an example of the approach.

Hitachi chose to set bias for a MOL at 1000 Hz. However, the output vs. bias curve at that frequency exhibits a rather broad peak (see Fig. 1), and the resolution of the microprocessor was deemed inadequate to strike a really definitive bias point. At 5000 Hz the MOL peak is considerably sharper, and

Fig. 1. The more sharply defined

optimum bias point at 5 kHz makes that frequency a

more suitable choice for

bias adjustment.

-30 -20' -O 0 +10 +20 +30 +40 BIAS CURRENT %)

at the same time output -level variations from the tape (resulting from drop -outs, variations in tape -to -head contact, etc.) are not likely to confuse the adjustment process.

In a study of various representative tapes, Hitachi determined that the bias level giving peak output at 1000 Hz is roughly 33 percent higher than that which gives a 5000 -Hz MOL for "normal" ferric -oxide tapes, roughly 25 percent higher for Cr02 tapes, and 11 percent higher for ferrichrome tapes. With that statistical information, Hitachi was able to create a system that adjusted for MOL at 1000 Hz while actually testing the tape at 5000 Hz. A tape -type switch must still be used to make sure that the right correction factors are introduced.

The JVC machine will take on almost any tape without the need to throw a switch to identify its generic type. On the other hand, the JVC machine presumably doesn't offer the finer degree of resolution possible when the microprocessor is re -

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If you've been looking forward to moving up to where the CB action really is, now's your chance... with the fabulous Cobra 2000GTL base station.

Because the 2000GTL has everything CB-ers in general and sidebanders in particular -have ever dreamed about. It's the only base station with built-in 6 -digit frequency counter, that lets you check both your transmitted and received signals with laboratory precision. The counter becomes an LED digital clock at the push of a button, and will, if you choose, turn on the radio automatically. Dual back -lit meters measure percent modulation, SWR,-signal strength and RF power. "DynaMike Plus" permits full talk power even when you're not close to the mike.

Other important features include voice lock with coarse/fine tuning and headphone and auxiliary audio output jacks.

But it's in noise reduction where the 2000GTL really stands out above the crowd. In addition to switchable noise blanking and automatic noise limiting, . the 2000GTL's receiver circuitry is designed to achieve sharp reduction of intermodulation and cross- modulation rejection. In addition, the SSB receiver employs a 6 -pole, narrow -band crystal -lattice filter that provides excellent adjacent -channel rejection and noise

reduction. (In SSB transmit mode, this same filter assures maximum carrier suppression.) The AM receiver is dual conversion, using crystal and ceramic filters. All this is topped off with separate IF strips for AM and SSB. The bottom line is quiet performance that must be experienced to be believed.

To assure highest quality sound, the 2000GTL has a separate speaker in its own enclosure. A second speaker may be added as a remote unit if you wish.

Best of all, now's the time to get everything the current state (DI the art makes possible- at a price the serious CB-er can afford. You may never get ano:her chance like this to move up where the action is.

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For information, write to PO Box 1691, Bridgeview, IL 60450 CIRCLE Na 9 ON FREE INFORMATION CARD


Fig. 2. A high -quality tape exhibits an almost perfectly flat frequency

response after adjustment.

) HIGH QUALITY TAPE BEFORE ADJUSTMENT 111111119

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AFTER ADJUSTMENT I 10 90 SO inn 900 500 IK 2K 5K 10K 20K

FREQUENCY (Hz)

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AFTER ADJUSTMENT

BEFORE ADJUSTMENT n 500 IK 2K 51( 1OK 20K

FREQUENCY (Hz)

quired to "search" only a comparatively narrow range of bias - level options.

The "Search." A hunt through various stepped levels of bias is how these machines accomplish their jobs. In at least one case, the bias descends in steps and then ascends; the final level chosen is the average of the MOL's determined by the descending and ascending sequences. The Hitachi deck is a three -head machine and is thus able to present data immediately to the microprocessor. The JVC has two heads and must rewind the tape (which it does automatically as part of the test sequence) before it can play the recorded test signals and "read out" to the control circuits.

A similar hunt takes place during the subsequent automatic adjustment of recording equalization, but EO is handled with varying degrees of sophistication. The Hitachi system appears to be the most complex, with shelving frequency -response characteristics below 10,000 Hz and peaking characteristics centered at 14,000 Hz. The JVC and Technics systems appear to provide comparatively simple filters with hinge points located somewhere in the midfrequencies. Whether the intricate mechanism that Hitachi has devised will be worth its weight in tape is a question that can be answered only after some serious experimentation with it.

For the cassette decks in this group, it is also necessary-or at least convenient-to provide some means of normalizing a tape's input/output characteristics (sensitivity, in other words), so that the level -dependent noise -reduction systems they have built in will function properly without further fussing by the user. Such facilitiés have been provided in the JVC and Hi- tachi decks, and they promise to be a real boon to those who have become disenchanted with noise reduction while being unáble. to get at the calibration controls that would make it work right. Dolby Laboratories, to name one manufacturer, does not encourage its licenseesto provide accessible calibration controls, though some licensees make such provisions. But this policy leaves the user at the mercy of whatever tape he happens to be using-and at the mercy of the person who performed the initial calibration at the factory. (As independent tests have shown, the cassette -deck industry does not always distinguish itself by providing the best Dolby tracking imaginable.)

16

Fig. 3. A low -price tape shows obvious deficiencies in performance, but is much improved in any case after the adjustment sequence.

The Specs. The control circuits in these self-adjusting machines, being digital, cannot offer continuously variable settings. Their search proceeds in discrete steps as governed by their memories. The Hitachi machine provides 96 steps for bias level, obtained through a 4 -bit converter and a 3 -bit float- ing-point system. The EO and sensitivity adjustment functions have 16 steps, each of 0.5 dB. The JVC machine has 32 steps for bias, 15 for sensitivity, and 7 for equalization. These differences are reflected to a certain degree in the specifications for the two machines. With a good tape, the Hitachi is said to maintain a frequency -response tolerance of ±0.5 dB over much of the audio frequency range. JVC's deck is typically ±1 dB according to the same criterion. Harmonic -distortion ratings are difficult to compare because of differences in testing.

Suffice it to say that both machines are rated in the range of 1 percent total harmonic distortion for recording levels below those that would cause tape saturation. Figure 2 shows Hita- chi's curves for a high -quality tape before and after adjustments for sensitivity and frequency response have been made. Figure 3 presents the same data for an inexpensive tape. (It should be pointed out that there is a substantial price difference between the Hitachi and JVC machines. Final Hita- chi pricing has not been announced, but a figure of $1000+ is anticipated. You'll find JVC's KD-A8 considerably easier on the pocketbook.)

I look forward to a flood of these self-adjusting tape decks within the coming year or so. The technology is here in an affordable format, and the wonders it can perform (refer to Fig- ures 2 and 3 again) have to be just irresistable to someone who takes his tape recording seriously.

When the trend is fully established, there will be no more tape jungle for the consumer to flounder through. He will be able to buy an armload of different manufacturers' cassettes, take them home, and in the course of a civilized, low-pressure evening decide for himself what his brand is going to be, without the worry that a noncompatible machine is making a good tape look bad. By the same token, tape manufacturers will be able to concentrate their full efforts on making a genuinely better tape. It will not be just a somewhat better tape that has been compromised a little because it must match the performance and adjustment profile of the tape decks already in the hands of potential customers.

POPULAR ELECTRONICS


FISHER INTRODUCES THE WORLD'S FIRST CASSETTE DECK WITH WIRELESS REMOTE EDITING.

Tape recording will never be the same.

In Fisher's 41 years of audio leadership, we've introduced many important high fidelity "firsts." But we honestly think the new CR4025 tape deck is one of our most exciting and practical innovátio:s.

Remote electronic editing is as important an advance in tape recording as the cassette.

Now for the first time, you can really enjoy creating your own persona: music library from.FM broadcasts or record al- bums. The editing is done electronically while recording. A great leap forward from the old way of recording... without jump- ing up and down every 3 minutes to edit.

Fisher's wireless remote electronic editor makes tape recording a pleasure. The CR4025 tape deck has a built-in wireless receiver that operates the deck's solenoid -actuated Pause mechanism. The remote control transmitter operates the Pause control instantly from úp to 20 feet away. Relax, listen, and capture the selections you want to keep at the push of a button.

Zap! You eliminate any commercial or announcer's voice from your off -the -air FM broadcast recording .. or skip any unwanted track on an album you're taping from.

Of course, this fantastic convenience wouldn't be worth much if you had to sacrifice performance. Fortunately, you don't - ie CR4025 has the excellent frequency response and extremely low wow & flutter that you expect from Fishe:, plus Dopy noise reduction br clean, nose -free recordings.

The Fisher' CR4025 is priced at $270* and is available at selected audio stores or the audio department of your favorite department store. New guide to buying high fidelity equipment. Send S2 for Fisher Handbook, with name and address to Fisher Corp., Dept. H, 21314 Lassen St. Chatsworth, Calif. 91311.

`Manufacturer': suggested retail value. Actual selling price is at the sole discretion of the individual Fisher dialer.

FISHER The first name in high fidelity.

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CR4025

© 1978 Fisher Corp., Chatsworth, Calif. 91311 CIRCLE NO. 190N FREE INFORMATION CARD

Dolly is registered trademark of Dolby Laboratories.


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Fingertip control of all microprocessor calculations; data readout in bright LED digits from solid oiled walnut console.

Aerospace -designed transmitter! Its wind speed and direction instruments are among the most sophisticated available. Rather than relying on friction -causing reed switches or other mechanical devices, they utilize solid- state infra -red sensors, and transmissive optical encoding. It offers unprecedented accuracy and within one -tenth of a mile per hour!

The remote transmitter unit with its windcup and weathervane mounts easily on your TV antenna or other outdoor mast for years of dependable, trouble -free service! It's actually been wind -tunnel -tested for strength and durability.

Remote transmitter mounts on TV antenna mast, transmits data to your console through cable supplied.

-

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New Heathkit Weather Computer Now...with your own computerized weather station, you can have

the temperature (indoors and out)...wind speed and direction ...the wind chill factor...the barometric pressure ...the time and date

...plus much more...right at your fingertips!

There's nothing else like it available today! A personal weather computer that not only monitors the current weather data, but also computes significant changes and stores wanted data in its memory! So now, for the first time, you'll have all the weather information you need for your personal and business planning!

Unique digital data display The handsome solid oiled walnut computer console features large, bright, LED numerals, displaying up -to -the - second data on the time (AM, PM or 24 hour format) and date; indoor and outdoor temperatures (in your choice of Fahrenheit or Celsius); wind speed (in miles per hour, kilometers per hour or knots) and direction on a 16 -point compass plus barometric pressure in millibars or inches of mercury.

The instrument's on -board microprocessor even calcu- lates the wind chill factor at the touch of a button. It also stacks barometric pressure readings in memory, so it can compute the rate of rise or fall on command! The barometer readings are derived from a newly -developed piezo resistive silicon bridge transducer that senses the most minute changes in pressure. It's the first and only truly digital electronic barometer!

An electronic almanac! The Weather Computer stores high and low temperatures as well as the time and date at which they were recorded. In addition, it records the highest wind gust speed and time, ready for instant recall. The data is stored in memory until you choose to clear it.

For serious weather research purposes, the instrument can be connected to a chart recorder for hard copy records. And, it can be interfaced with any compatible digital computer for even more sophisticated weather charting and forecasting. As a final thoughtful design touch, the instrument even makes provision for battery back-up to preserve the data stored in memory in case of power failure.

The Electronic Weatherman is a truly unique computerized weather instrument, offering capabilities never before available to the layman with a serious interest in

the weather. For business or personal reasons, you'll find it an investment that can pay for itself many times over!

Easy -to -build kit form If you want the fun (and savings) of building it yourself, you'll find the Heathkit Digital Weather Computer surpris- ingly easy to build, thanks to the fully -illustrated step-by- step assembly manual. Or, you can order yours assembled, ready to install and use.

The Heath Electronic Weatherman comes complete with remote transmitter unit, 100 feet of connecting cable and a solid oiled walnut console. Order yours now and be prepared for the weather, whatever comes!

For Fastest Service, Order by Phone CALL (616) 982-3411

1

HEATH HEATH COMPANY Dept. 010-522

Schlumberger Benton Harbor Michigan 49022

Gentlemen: Please send me... Heathkit Weather Computer Kit(s) (10-4001) with 100' of cable each (IDA -1290-2) @ $383.90 plus $3.95 shipping and handling each. Assembled Digital Weather Computer(s) with 100' of cable each (IDW-4001) @ $595.00 plus $3.95 shipping and handling each.

I enclose check money order for S

or, Please charge to my VISA Master Charge: Code =

Acct. =

Signature

Name

Address

Exp. Date

(Necessary to send merchandise)

City

(Please Print)

State Zip G X -360

Prices are mail order and effective through May 15, 1979.

APRIL 1979 CIRCLE NO. SON FREE INFORMATION CARD

19


Julian Hirsch Audio Reports distortion detection loop and pulse - counting demodulator are featured

CIHIRSCtI- HOUCK : LABS REPORT

THE Model KT - 917 FM tuner from Kenwood uses unusual and innovative circuits

to minimize or eliminate most of the conditions that normally lead to distortion in FM reception. The tuner also features three degrees of i -f selectivity and a multiple tuned circuit front end that gives outstanding interference rejection.

Kenwood has determined that the distortion levels in many FM tuners are un- necessarily high because the user has no means of accurately tuning for minimum distortion. Afc merely corrects for gross tuning errors, and even crystal - controlled synthesized tuning systems cannot guarantee that the pass -bands of the i -f and detector sections are accurately aligned with each other. Ken - wood's sólution, therefore, was to design a "Distortion Detection Loop" (DDL) system that automatically nulls out tuning distortion. The DDL is used in

combination with a highly linear pulse - counting type of FM detector.

The tuner measures 18'/4"D x 181/e"W x 6'/8" H (46.4 x 46 x 16.2 cm) and weighs 33.1 lb (15 kg). Suggested retail price is $1000.

General Description. The tuner has a standard slide -rule tuning dial behind a window that also covers the large and easy -to -interpret meters. Two of these are conventional zero -center tuning and signal -strength meters. A third is a combination meter that can be switched to indicate either deviation or multipath distortion. The signal -strength meter is calibrated directly in 10 -dB steps from 0 to 90 dBf. The deviation meter registers peak frequency deviations from zero to 120% of the rated 75 -kHz maximum.

Four lights above the dial scale come on separately to indicate when muting is in operation, a stereo signal has been tuned, the tuner has been set for AUTO

mono/stereo reception, and the Distor- tion Detection Loop is in operation. Tun-

The Kenwood Model KT -917 FM super tuner nulls tuning distortion automatically

ing of the Model KT -917 is performed in the same manner as with any conventional tuner, tuning until the zero -center meter is in the center of its scale. The difference here is that a couple of seconds after the tuning knob is released, the DDL system automatically com- pletes the tuning for minimum distortion. Then the DDL indicator comes on.

surface acoustic filters provide superior selectivity

The tuner's muting threshold can be set at either 20 or 40 dBf, or the muting system can be disabled altogether. A horizontal row of lighted green dots above the dial scale increases in length as the tuner's i -f bandwidth control is

switched from narrow to normal to wide. A "quieting control" permits the user

to select the tuner's operating mode. In

AUTO, either a mono or a stereo broadcast will be heard correctly. With the control set to the STEREO position, the tuner unmutes only for stereo signals. (In this position, if the signal strength drops low enough to make noise a prob-

lem, a multiplex filter automatically blends the left and right channels at the high frequencies to reduce the noise with no appreciable degradation of the stereo image and with no loss in high -frequency response.) All signals received, whether mono or stereo, are delivered to the amplifier in the mono format when the switch is set to MONO.

Pushbutton switches are provided for switching between deviation and multipath distortion display on the dual-purpose meter; dimming the panel lights; and connecting either of two antenna systems to the tuner. The normal A and B antenna connectors are 75 -ohm coaxial jacks. The B antenna connector is

paralleled by binding posts for a 75 -ohm antenna and a 300 -ohm antenna. The purpose of the dual antenna inputs is to simplify the orientation of antennas for minimum multipath distortion. By placing the two antennas at suitable angles to each other, one has a choice of two receiving conditions for every station. If

the antennas are oriented for minimum multipath distortion on one or more stations, it will often be possible to improve reception appreciably by selecting the appropriate antenna without the cost and inconvenience of a rotatable antenna system.



Vertical and horizontal outputs on the rear apron permit an accessory oscilloscope to be connected to the tuner for displaying multipath distortion. There are also separate pairs of fixed and variable -level audio output jacks; a slide switch for changing the deemphasis time constant from the normal 75 to 25

µs for use with an external Doiby adapter; and a single unswitched ac outlet on the rear apron.

The two MOSFET r -f amplifier stages in the tuner contain a total of seven tuned circuits. Two tuned circuits pre- cede the first amplifier stage, two are between stages, and three couple the amplifier to a four -diode (Schottky) balanced mixer. Although it is complex and expensive, this approach gives the tuner a degree of immunity to overload and spurious -signal generation that is rarely, if ever, found in home -entertainment equipment. The local oscillator is followed by two buffer stages and other circuits. Both the oscillator and the second buffer stage are tuned, and the nine - section tuning capacitor is unique among the tuners we have seen.

The 10.7 -MHz output from the mixer is linearly amplified by a FET stage whose output is then processed for driving the signal -strength and multipath- distortion meters. The distortion meter responds to the amplitude modulation imposed on an FM signal during muf- tipath distortion. The signal is passed through an accurate logarithmic converter before it is applied to the signal - strength meter.

row of green LEDs indicates selected i -f bandwidth

Following the linear i -f amplifier is a

series of four surface acoustic filters (SAFs) that give the tuner its selectivity. (The SAFs operate by propagating acoustic waves across a ceramic sub- strate from an input transducer and receiving the waves in an output transducer that restores them to electrical form.) The SAF has excellent bandpass flatness, steep rejection skirts and good group delay characteristics, which are necessary for low distortion and good separation in stereo reception. Only one filter is used in the WIDE mode, two in NORMAL, and all four in NARROW. Filters coupled by amplifier stages are

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switched in and out by diodes that are operated by dc control signals.

The 10.7 -MHz i -f signal is converted to 1.96 MHz and amplified before going to the pulse -counting detector. Follow- ing detection, the signal is processed by

a sample -and -hold stereo demodulator. The composite stereo signal is sampled at a 38 -kHz rate, which is synchronized with the 19 -kHz pilot signal, to convert it

to left- and right -channel audio signals. Instead of the usual lowpass filter to re-

move 19- and 38 -kHz components from the audio outputs (which can effect the flatness of a tuner's high -frequency re-

sponse), the Model KT -917 has a pilot - canceller circuit ín which the regenerat- ed pilot carrier is used to cancel out the 19 -kHz pilot signal in the detected output. rlis extends the tuner's flat audio response to beyond 15,000 Hz, while keeping 19 -kHz leakage to low levels.

Laboratory Measurements. Be -

APRIL 1979 21


Product Focus The Distortion -Detection Loop (DDL)

in Kenwood's Model KT -917 tuner is a

form of amplified afc, but with an important difference. Unlike a conventional afc, which tunes the local oscillator to produce a zero dc output from the detector. the DDL tunes for minimum second -harmonic distortion in the detected signal. This automatically compensates for any asymmetry in the i -f or detector, which is ignored in an ordinary afc system or in a

manual -tuning system with the aid of a

zero -center tuning meter setup. Since there is no way to measure the

second -harmonic distortion in a complex musical program, the Model KT -917 must supply its own test signal to operate the DDL. How this is done is illustrated in Fig. 1. As in any afc system, the dc local

LOCAL OSC

CD TUNING

KNOB

TOUCH DET

PC D

oscillator control voltage is present. This signal varies the local oscillator frequency through a Varactor diode and is combined with a locally generated 95 -kHz signal that also frequency modulates the local oscillator. This is equivalent to having the FM station transmit a 95 -kHz sub - carrier at a low level of modulation.

At the output of the tuner's detector, the 95 -kHz signal and any harmonics of it are separated from the stereo program by a high-pass filter. In a secondary control loop, the output of the 95 -kHz oscillator is passed through an electronically controlled phase -shift network whose output is compared to the phase of the detected 95 -kHz signal in Phase Detec- tor #2. This process compensates for any phase shifts that occur in the modu-

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ORIGINAL MODULATION

lation, amplification, and detection processes. so that the internal 95 -kHz signal is exactly in -phase with the detected 95 - kHz component.

The phase -corrected 95 -kHz signal is

passed through a frequency doubler. The resulting 190 -kHz signal feeds one port of Phase Detector #1. The other port receives the filtered detector output, which consists of the 95 -kHz signal and a small amount of second -harmonic distortion at 190 kHz. The phase of this distortion is a

function of the direction of mistuning and its amplitude is proportional to the amount of the tuning error. Hence the output of Phase Detector #1 is proportional to any distortion created by a tuning error, although the second -harmonic distortion level is extremely low (about

PHASE DET*2

VARIABLE PHASE

REFERENCE OSC

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Fig. 2. Sequence of waveform changes in

pulse -count demomulation.

Fig. 1. Block diagram showing operation of the Distortion Dectection Loop (DDL)

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100 dB below normal stereo program levels). A low-pass filter removes higher frequencies from the error signal, leaving a

very small dc error voltage. Because of its extremely low level, it is necessary to

use a switching (chopper) amplifier to

amplify the dc error signal to useful levels without risking any drift that could in-

troduce a tuning error. The phase detector and error amplifier are stabilized against drift by a 10.000 -Hz switching signal that operates on the input and output signals to form an effectively direct - coupled high -gain amplifier with virtually no dc drift. After filtering to remove higher frequency components, this error signal is combined with the internally generated 95 -kHz signal and sent on to the frequency control diode in the local oscillator.

A three-part logic system disables the DDL until a signal has been tuned in

manually. The tuning knob functions as a

touch detector. The detected 60 -Hz hum is rectified and the resulting dc voltage goes to the DDL logic section. The logic also receives a dc level from the tuner's muting system and another from the detected 95 -kHz signal. Unless a signal of sufficient strength and tie necessary amount of 95 -kHz modulation are present on it and the tuning knob is released. the DDL system is inhibited.

The pulse counting detector (PCD) is

another novel circuit feature of the Model KT -917. Pulse counters are not new. having been used for decades for accurate linear FM demodulators in laboratory instruments and other critical applications. Until recently, they were too complex and expensive for use in consumer products. especially at the high i-fs employed in FM tuners. High speed ICs and transistors are now available at moderate cost, making the PCD practical for use in

a high -quality FM tuner. The principle of the PCD is very sim-

ple. The FM signal, at the intermediate frequency, is converted to a series of short pulses of constant width and amplitude. which occur at a frequency that is

the same as that of the received signal. If

the pulse train is clamped to a fixed (or zero) voltage level, its average value ex -

cause many of the specifications of this

tuner exceed those of good laboratory - grade signal generators, we did not expect to be able to fully confirm Ken - wood's ratings. Specially designed or modified signal generators were used by

Kenwood during the development of the tuner and to establish its performance ratings. Our tests were performed with a

standard Sound Technology Model 1000A FM signal generator.

The measured sensitivity of the tuner was as rated. Measured distortion and noise were essentially those of our signal generator. Only by shutting off the modulation circuits in the generator (CW

multipath meter is one

of very few that is

genuinely effective mode) could we achieve the 84 -dB mono S/N reading. Since the modulator was required for a stereo measurement, to supply the pilot -carrier signal, we

were limited to approximately the 70 -dB range of the generator. For our image - rejection measurement, we used a

Boonton Model 202B signal generator, whose maximum output of 200,000 µV was not sufficient to produce a detectable signal at the image frequency, leaving us with an inconclusive but very impressive measurement of greater than 106 dB.

The only unexpected behavior we en- countered when testing the tuner was the relationship of the DDL to stereo channel separation. The DDL worked perfectly and always produced minimum distortion, no matter how the tuning was set when the knob was released. How- ever, when we first measured the stereo channel separation, with the tuning set

"dead center," separation was 36 to 43

dB, which is perfectly adequate but somewhat short of Kenwood's claimed 50 to 60 dB. After confirming that the signal generator was correctly adjusted,

0.5 we investigated further and discovered that releasing the tuning knob when the signal was barely tuned in, just at the

0.3 point where the muting was overcome, gave much improved readings. We read

LL typically 50 to 55 dB between 30 and 2000 Hz. With WIDE bandwidth, it exceeded 60 dB between 80 and 160 Hz

and decreased smoothly to between 33

and 35 dB at 15,000 Hz. There was little difference in separation between IF

BAND switch settings.

APRIL 1979 (Continued on page 28) 23

RATIO

-<.;0 4 ----DETECTOR

J Q

w

-W 0.2

PULSE -COUNT

0.1 DETECTOR

-aóo -200 0 FREQUENCY (kHz)

+200 +400

actly follows the modulating waveform of the FM signal.

Figure 2 shows the segifence of waveform changes in the Model KT -917's PCD. The modulated FM signal. after conversion to a lower i -f, is amplitude lim-

ited to form a square wave whose zero - axis crossings coincide with those of the input FM signal. Every time the Limited

waveform goes through the zero -voltage axis in a po>itive direction. a negative trigger pulse is generated by the trigger circuit. The trigger pulses drive a

monostable multivibrator that produces pulses of uniform width and amplitude every time a trigger is received. Since the low and high levels of the pulse train are fixed. the average value of the multivibrator's output follows the waveform of the

original modulation. It is only necessary to pass the pulse train through an inte- grator or low-pass filter to remove the

carrier -frequency components and re- cover the audio.

The advantage of the PCD over a conventional tuned FM detector is illustrated in Fig. 3 (from data supplied by Ken -

wood). Since it depends on tuned circuits for its operation. the differential gain (the

slope of the detector output voltage ver-

sus input frequency) changes slightly with frequency. The result is an output voltage that is not exactly proportional to

the input frequency and distortion is

created. The lower curve shows the al-

most constant differential gain of the

PCD over a very wide frequency range. If

the pulses are all identical, the output of the PCD is theoretically perfect)/ linear over a very wide frequency range.

Aside from its greater circuit complexity. the PCD also delivers an audio output voltage proportional to the deviation as a' percentage of the operating frequency of the signal. At 10.7 MHz. a 75 -kHz deviation is only 0.7% of the operating frequency, and the output is very low. By converting the 10.7 MHz i -f to 1.96 MHz, the same signal is now deviating 3.8% of the carrier frequency and the output is in-

creased five -fold. This improves the S/N by about 15 dB. as compared to a PCD system operating at 10.7 MHz.

Fit. 3. Differential gain vs. frequency for ratio deUector and pulse -count deter ten- showing distortion performance.


ta áÉOit..i.:. O..

i1

When you do,you'll probably pick CIE. You can't afford to settle for

less when it comes to something like electronics training that could

affect your whole life. 24 POPULAR ELECTRONICS


When you shop around for tires, you look for a bar-

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If you talked to some of our graduates, chances arc you'd find a lot of them shopped around for their training. They pretty much knew what was available. And they picked CIE as number one. Why you should shop around yourself.

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With CIE's Experimental Electronics Laboratory...

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F E=NM EMI all MI= Ell ECleveland Institute of Electronics, Inc.

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E YES ...I'm shopping around for the right kind of career training in electronics troubleshooting-and CIE sounds well worth looking into. Please send me my FREE CIE school catalog-including details about troubleshooting courses- plus my FREE package of home study intbrntation! PE -87

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APRIL 1979 27


Performance Specifications

Specification Usable sensitivity

(Mono)

50 -dB quieting sensitivity

(Mono) (Stereo)

S/N ratio (Mono) (Stereo)

Total harmonic distortion (Mono; 1000 Hz)

(Stereo; 1000 Hz)

CAPTURE RATIO

Alternate channel selectivity

Adjacent channel selectivity

Stereo separation (1000 Hz)

(50 to 10,000 Hz)

(15,000 Hz)

Frequency response

Spurious response ratio Image response ratio I -f response ratio AM suppression ratio

Subcarrier product ratio SCA rejection ratio Output level

(1000 Hz, 100% mod) Fixed

Variable Multipath output

Vert.

Horiz.

Rating

10.8 dBf (1.9 µV)

Measured

10.8 dBf (NORMAL) 13 dBf (NARROW) 11 dBf (WIDE)

15.8 dBf (3.411,V) 17 dBf 37.2 dBf (40 µV) 36 dBf

90dB 84dB

0.03% WIDE

0.06% NORMAL

0.15% NARROW

0.04% WIDE

0.09% NORMAL

0.12% NARROW

0.8 dB WIDE

1.4 dB NORMAL

1.7 dB NARROW

35 dB WIDE

60 dB NORMAL

60 dB NARROW

N/A

84 dB (unweighted-approx. 70 dB gen. residual)

0.064% (approx. gen. residual) 0.064% 0.09% 0.062% (approx. gen. residual) 0.062% 0.17% 0.8 dB/0.73 dB (45/65 dBf) 0.8 dB/0.73 dB 2.1 dB/1.3 dB

44dB 44dB 82dB

6.3 dB (wIDE) 5.4 dB (NORMAL) 15.5 dB ((NARROW)

(Continued from page 23)

We were struck by the fact that the selectivity was approximately the same in both NORMAL and WIDE bandwidth modes. Our measurement of 44 -dB alternate -channel selectivity would be considered marginal for most FM tuners if it were the only one available. How- ever, we never experienced any interference problems using the tuner in New York City, where more than 50 stations can be received. In this area, which is subject to adjacent- and alternate -channel interference, the NARROW mode gave the tuner exceptional selectivity.

Dial calibrations were accurate to within 200 kHz and usually to within 100 kHz. The signal -strength meter indicated within 4 dB of the actual input signal level over its full range. The deviation meter's indications were about 15% greater than the actual deviation, which is of little importance for the meter's purpose. The multipath-distortion meter was one of the very few we have seen that is genuinely effective. Even a slight amount of multipath distortion produced an appreciable indication on the meter during modulation, and a signal without multipath did not cause any detectable pointer movement.

200,000 microwatts was not sufficient to produce detectable image signal

We were unable to use the scope outputs on the rear of the tuner as a multipath or tuning indicator. The reason for this was that the 0.01 -volt vertical output was insufficient to produce a useful deflection on several scopes we tried.

User Comment. Since the tuner we tested was one of the first Model KT -917s to enter this country, we have no way of knowing if its unorthodox tuning for maximum stereo separation is inherent or a peculiarity of our test sample. Whatever the case, it is of minor importance, since broadcast stations are required to maintain only a minimum of 30 dB separation and virtually no phono cartridges or records are even that good. Needless to say, the tuner will never degrade the audible separation of the received program.

Operation of the DDL is very effective. With most tuners and receivers, normal tuning errors, even with great care, can


60 dB WIDE

55 dB NORMAL

50 dB NARROW

50 dB WIDE

45 dB NORMAL 40 dB NARROW

40 dB WIDE

38 dB NORMAL

33 dB NARROW

10-16,000 Hz +0.2/-0.5 dB 125 dB 125 dB 125 dB 70 dB

70 dB 75dB

0.75 V, 60 ohms 0-1.5 V, 60 ohms

0.01 V, 10,000 ohms

0.5 V, 3000 ohms

51.0dB 50.5dB 54.5dB 39.5dB 38.0dB 35.5dB 33.0dB 34.5dB 34.0 dB 30-15,000 Hz +0.2/-0.3 dB

Greater than 106 dB

70 dB (45 dBf) 73 dB (65 dBf) 66 dB

Confirmed 0-1.86 V


easily degrade a 0.1% distortion condition to 0.3% and even 0.5%. As Keh- wood points out, afc is no solution because its operation requires an error voltage that itself introduces a tuning error. The DDL, on the other hand, will give minimum second -harmonic distortion every time, with literally nothing the user can do to mistune the Model KT -917. (On weak signals of less than 25 to 40 dBf, the DDL may not lock on, in

which case, the DDL indicator will not light. In any case, signals in this range will have their distortion masked by noise.)

can deliver last measure of

performance possible

Basic operation of the tuner was superb! We usually preferred to set the muting threshold at 20 dBf, although one might find 40 dBf preferable in a very strong signal area to eliminate less powerful signals as the band is tuned. (The muting thresholds were very close to the indicated values, measuring 21 and 42

dBf.) The tuning mechanism operates with typical Kenwood smoothness, and the dial calibration was good enough to permit tuning to be set with the power off and, upon turning on the power, to hear the desired station perfectly tuned by the DDL system.

The signal -strength meter is highly in- formative because it displays the actual received signal levels in a form that can be related to the dBf ratings that appear in manufacturer ratings and our test reports. It is also useful in conjunction with the multipath meter for orienting a directional antenna. An antenna position that yields minimum deflection on the multipath meter and close to a maximum on

the signal -strength meter is certainly the best for any given station. We never had

occasion to use the deviation meter, which appeared to operate rapidly enough to give a useful indication of

peak modulation levels. Although in a

few less critical cases the tuner fell short of meeting its published specifications, there were at least as many of the far more important measurements that sur- passed specs by wide margins.

In our opinion, only two i -f bandwidths would have been sufficient for any prac-

tical situation. With both the normal and the wide bandwidths giving virtually identical selectivity, distortion, and separation readings, one of the two was re- dundant. Our only other criticism is the unreasonably low output from the tuner's vertical scope terminals.

It would be difficult to show that a "super tuner" such as the Model KT -917 actually sounds better than a much less expensive and elaborate tuner on most typical broadcast material. After all, when every characteristic of the tuner is

many times better than the corresponding property of the program material, one cannot expect sonic miracles.

The justification for a tuner like the Model KT -917 is that it overcomes the last vestige of human error in tuning and can be depended upon to deliver the last measure of performance possible on every station tuned in. As we see it, this is

the rationale for the Model KT -917's existence, and it is a sufficiently convincing argument for those people who depend on FM sources for a substantial portion of their listening pleasure to make the considerable financial investment that this tuner represents.


code Dolbyized FM broadcasts with or

without simultaneous recording. The deck has separate bias and

equalization switches for ferric -oxide, chromium -dioxide, and ferrichrome tapes. Other features include a dual- capstan tape drive; front -panel Dolby - level calibration control and test oscillator switch; vernier bias adjustment control for matching the requirements of different tape formulations; peak - responding meters; and adjustable

° ", 9 -- / . ! -- MN

° - -1,- "T 1 z

--- ° DA. } II i'. .---

-Ss, ^^° 1 -F 0 - -i '

.... s - .ice

Three heads and variable bias adjustments are features of t h e Realistic SCT -3 o stereo cassette deck

"memory rings" that provide reference settings for the recording and playback level controls.

The cassette deck measures 18" W x10`Dx53/a"H(45.7x25.4x14.6 cm) and weighs 16.5 lb (7.5 kg). It features walnut -veneer wood side plates and a satin -gold finished front panel. Suggested retail price is $399.95.

General Description. The Model SCT-30 resembles many other front -

1 HIRSCH.

THE Realistic

HOUCK Model SCT-30 is

currently Radio Shack's top -of-

_ ' the -line cassette deck. This front-loadina. three -head

deck has separate Dolby noise-reduction systems for record and playback. Thus, programs can be monitored while recording with the same frequency response and noise level. The Dolby system can also be used to de-

loading cassette decks, with its cassette loading well at the left of the front panel. Under the well is the customary bank of levers for operating the trans - port mechanism. A window in the cassette well door exposes almost the entire cassette to view during opera - tion. and back liahtina is provided.

APRIL 1979 29


separate record and playback Dolby for true tape monitoring

Bias and equalization for the various tape formulations can be set up with two lever switches. The BIAS switch has positions for Cr02, ferric - oxide, and FeCr formulations. The Eo switch has corresponding legends for 70, 120, and 70 p.s. (These time con- stants are for playback; recording equalization is also switched so that the 70-1Ls characteristics of the first and third positions of the EO switch are not identical in their total effect.) A similar switch operates the Dolby system. Its third position is labelled FM, which is used to process audio from an FM station that Dolby -encodes its programs. In this mode, recording -level controls are disabled and the input level is controlled by two screwdriver controls (on the rear apron), using the test tones periodically transmitted by FM stations that use Dolby processing. The FM mode also converts the 75-µs deemphasis of the tuner's output to the 25-1s required by the Dolby noise -reduction system:

The two RECORD controls are concentric. A plastic ring that surrounds them can be set for conveniently returning to a predetermined gain setting. There is a slight detent at the ring's index mark. The OUTPUT (playback) level control also has a "memory ring."

Laboratory Measurements. For our tests, we used the high-energy ferric -oxide Supertape Gold, TDK's AD and SA, Sony's FeCr, and Memo- rex's High Bias tapes. The overall record/playback frequency response with any of these tapes was well within the deck's published ratings. In fact, all the tapes performed very similarly to each other when the bias was adjusted according to instructions for each tape. The low -frequency "head ripples" in the response curve were rather low in amplitude, although they extended up to about 700 Hz. They did not reduce the low -frequency response, which was almost flat down to our measurement limit of 20 Hz.

The overall response was typically well within ±2 dB, referred to the 1000 -Hz level, from 20 to 16,000 Hz with all of the tapes at a -20 -dB re -

T 5dB

!l:

101

e

1 1ST C S 30

FREQUENCY (Hz)

-

0000 10000

Frequency responses at 0 and -20 dB for TDK AD at normal and maximum bias.

11111

IFNI% 9_ l .

MINI :Ir C /70 s i :.'I : ` 1111 ! 0l+iéfi.it;:R' - ... A i ®o1iA1

IFILIMIMIAII ' 'EMU FREQUENCY (Hz)

Frequency responses al 0 and -20 dB far Sony FeCr tape.

0000

.rte

10000

{:

r

T

d:

{

1 )c, 6

I7`ó

0.1

o 9.A9

IRL

0000

FREQUENCY (Hz)

Frequency responses at 0 and -20 dB for Memorex High Bias tape.

i

E

10000

cording level. The deck was slightly underbiased for TDK AD and Memo- rex High Bias tapes. However, with the bias adjustment set to its maximum limit, both tapes yielded very flat response curves.

Much more impressive than the flatness of the -20 -dB response curve was the performance at a 0 -dB recording level. With most of the tapes, the response remained flat to about 8000 Hz and did not roll off rapidly un-

- til the frequency exceeded 10,000 Hz.

(With TDK SA tape, using Cr02 bias and equalization, the 0 -dB response was flat to 10,000 Hz!) The 0- and -20 -dB response curves intersected at 13,500 Hz with Realistic Supertape, but with all other tapes, the 0 -dB response was always above the -20 - dB curve so that intersection never occurred. This indicates unusual freedom from head and tape saturation- one of the benefits of a good three - head design, since the recording and playback heads can each be de -



signed for their separate tasks. We observed that the Sony FeCr tape revealed more evidence of high -frequency saturation than other tapes, with its 0 -dB response rolling off smoothly above 2000 or 3000 Hz but never intersecting the -20-dB curve.

When we measured playback distortion as a function of recording level at 1000 Hz, we received a second surprise. Many cassette decks go into saturation just beyond their 0 -dB meter calibrations and distortion rises rapidly before the meter's pointer goes off - scale. The Model SCT-30, however, had to be driven to about +10 dB with most tapes before third -harmonic tape distortion reached the reference 3% level. (With TDK AD tape and the bias set to maximum to flatten out its re-

sponse, we had to go to +13 dB to reach 3% distortion!) At first, we won- dered if the recorded levels were lower than usual, but the Dolby points on the meters were within 1 dB of the correct 200 nW/m flux level for a standard Dolby tape. This means that the Model SCT-30 has a headroom of 7 to 10 dB beyond the Dolby level before the distortion reaches 3%. Therefore, Dolby -encoded FM programs can be recorded with fully effective Dolby operation with no risk of tape saturation and the resulting loss of highs and increased distortion. This is very rare in

cassette recorders, most of which cannot be recorded at levels greater than 3 or 4 dB above the Dolby level without excessive distortion.

On most recorders, if the FM Dolby signal levels are adjusted correctly for the Dolby system, with 50% modulation corresponding to a Dolby -level meter indication on the recorder, 100% modulated peaks will be at +6 dB and will almost certainly overload the recorder. The only alternative in

most cases is to set the Dolby tone from the FM transmitter (50% modulation) several decibels below the meters' Dolby points, which can degrade frequency response and noise reduction but will not distort. These examples are based on recording the signal without decoding, a theoretically preferable approach. Often, the easiest

playback distortion from 0 -dB recorded signal was very low 0.25% to 0.32%

solution is ,to decode the Dolby - encoded signal and -record it in that form at correct levels. We also found that Dolby tracking of the recording and playback circuits of the Model SCT-30 deck was excellent. There was less than 1 dB change in any part of the response from 20 to 15,000 Hz at levels from -20 to -40 dB when the noise -reduction system was operating.

Playback distortion from a 0 -dB recorded signal was very low, measuring 0.25% to 0.32% for most tapes and 0.63% with Sony FeCr tape. All of

our measurement's. were below the deck's 0.9% rating. Playback frequency response was within ±1 dB from 40 to 12,000.Hz with the TDK AC -337 120-µs test tape and ±2 dB from 40 to 10,000 Hz with the Teac 116SP 70-µs test tape.

The unweighted S/N ratio was about 50 dB, referred to a 3% distortion level. With "A" weighting, readings improved to between 53.5 and

55.3 dB, depending on the tape: With CCIRJARM weighting ánd the Dolby system switched in, S/N was about 64 dB with ferric -oxide tapes (Realistic Supertape and TDK AD} át normal bias settings. With bias adjusted for flattest response 'on tQK AD tápe,.tlie S/N improved td slightly greater than 66 dB, which is, the same reading obtained with TDK SA tape and Cr02 bias and equalization. The best S/N was measured with Sony FeCr tape, which was ah excellent 68.5 dB. Noise increased by 9.2 dB.through the microphone inputs at maximum gain.

An Aux input of 85 mV br a Mic in-

put of 0.3 mV was required for a 0 -dB reading on the deck's meters. The microphone input overloaded at a rather low 25 -mV input. Maximum ,playback level from a Ó -dB recorded signal was about 0.33 volt with ferric -bride tapes and 0.4 volt with TDK SA and Sony FeCr tapes.

The CCIR or DIN weighted peak flutter with a TDK 'AC -317 test tape

Performance Specifications

Specification Rating Frequency response (±3 dB)

Measured

Supertape 30-15,000 Hz 20-16,000 Hz ±2 dB (ST)

Cr02 30-16,000 Hz 20-15,500 Hz ±2 dB (SA)

FeCr 30-15,500 Hz 20-15,000 Hz ±2 dB (FeCr)

Overall S/N ratio 61 dB (Cr02, Dolby 49 dB (ST) CCIR weighted) 48.3 dB (AD) (unweighted)

50 dB (SA) 49.5 (FeCr) 53.5 dB (ST) 54 dB (AD) (A weighted) 54.7 dB (SA) 55.3 dB (FeCr) 64 dB (ST) 64.3 dB (AD) 66.3 dB (SA)

(CCIR/ARM, with Dolby)

68.5 dB (FeCr) Distortion at 0 VU Less than 0.9% 0.32% (ST)

0.28% (AD) 0.25% (SA) 0.63% (FeCr)

Crosstalk Under -60 dB -42 dB (TDK AC -352 tape) Wow/flutter Under 0.06% wrms 0.075% wrms (TDK AC -342)

0.09% wpk Erase ratio 70 dB Nót measured Output level At least 0.55 V 0.33 to 0.40 V for 0 dB

recorded signal Output impedance 10,000 ohms Not checked

(8 ohms, phones) Input impedance AUX 100,000 ohms Not checked

Mic. OK for 500 to 5000 ohms

Record bias frequency 105 kHz Not checked Fast forward/rewind time Under 125 s for C-60 96 s

APRIL 1979 31


was ±0.09%, and the JIS weighted rms flutter was 0.075%. In a combined record/playback measurement, readings were slightly higher. Speed was 0.5% fast. The deck required about 96 seconds to handle a C-60 cassette in both fast forward and rewind. This was faster than the rated time, but still rather slow. The 1000 -Hz crosstalk from right to left channel with a TDK AC -352 test tape was -42 dB. The meters had a fast response, with about 15% to 20% overshoot on a 0.3 - second tone burst, and a slow decay time that appeared to be on the order of a couple of seconds. Headphone volume was excellent, even with 200 - ohm phones.

User Comment. When we compared the sound of interstation FM tuner hiss entering and leaving the recorder, we found the two to be close with all of the tapes we used. It was virtually perfect when the bias was carefully adjusted. In taping FM broadcast programs, we could never hear any difference between the incoming and outgoing signals when we used the monitor button on the recorder or amplifier. Recording levels are

much less critical with this deck than with most we have used. We found it perfectly practical to record with the deck's meters regularly indicating in the range between 0 and +3 dB. With the meter pointers often pinned lo their right indexes, there was no auci- ble sign of compression, distortion, or loss of highs.

The Model SCT-30 lacks a few frills, such as memory rewind and microphone mixing, neither of which is likely to be missed by most cassette deck users. To compensate for this, the buyer gets one of the very few cassette decks, and possibly the only one at this deck's price, that can decode or record Dolby -encoded FM broadcasts without the risk of distortion and with fully effective Dolby operation. In its sound quality, this deck takes second place to none when recording from records and FM broadcasts. It is more limited for live recording purposes if one wishes truly high -quality results, of course, owing to the cassette medium and, perhaps, to the low -mike overload point.

Handling quality of the deck ranged from fair to good. When EJECT is pressed, the cassette well moves out

in a smooth, cushioned manner. Lev- ers such as FAST FORWARD disengage automatically moments after the end of a tape is reached-a neat feature. The action of the transport lever, though positive and smooth, does have a mechanical latch for locking purposes. Also, the levers are all the same size (except STOP) so, without il- lumination, one would be hard pressed to control the transport in a darkened room.

The foregoing does not detract from the overall fine value of this deck. Nat- urally, there are trade-offs to be made for the price. Raw performance is super. Variable bias adjustment; big, well -lighted meters; Dolby monitor; Dolby test -adjust facility; three tape heads; and the like more than make up for some noted shortcomings. And let's not forget the front -load facility, which is a pleasurable convenience, though transport start is delayed somewhat as heads are moved into position. In all, the new Realistic SCT-30 would be a fine addition to virtually any high -quality stereo component system when overall high performance is the overriding criterion. CIRCLE NO.102 ON FREE INFORMATION CARD

Denon DP -2500 record player offers direct drive with quartz control and dc braking

HIRSCH- g THE Model DP-

HOUCK 2500 record play-

LABS er introduced by . La Denon offers a

a quartz - controlled direct -drive turntable ánd a high -quality tonearm. The single -play, manually operated player is mounted on a 40 - mm thick wooden base.

The turntable features an ac motor with bidirectional servo control and dc braking to give it exceptionally fast start-up, speed -change, and shut- down times and very low flutter and rumble. A dynamically damped tone - arm reduces the effect of low -frequency tonearm/cartridge resonance. It

employs a lightweight rigid aluminum headshell with a four -pin plug-in design. The wood base is sandwiched with a viscous damping material to reduce resonances. The base is covered in a vinyl wood -grain (choice of blond ash or walnut) veneer and comes with a clear -plastic dust cover.

With the dust cover closed, the Model DP -2500 record player measures 19" W x 16" D x 7" H (48.3 x 40.6 x 17.8 cm) and weighs 26.5 lb (12 kg). Suggested retail price, $525.

POPULAR ELECTRONICS 32


General Description. Like other Denon record players, the Model DP -2500 has its cast -aluminum platter almost entirely above the motor - board and surrounded by a bevelled ring. On the sloping surface of the ring

are the turntable controls, including a

pushbutton power switch and a green indicator light, a 331/3- and 45 -rpm speed selector switch, and a momentary -contact button for starting and stopping the turntable. Stroboscope markings under the platter are visible through a window in the control ring.

The ac servo motor that drives the platter is controlled by a quartz crystal oscillator whose operating frequency is about 1.3 MHz. The feedback signal from the platter to the control amplifier is derived from a magnetized band on the inside rim of the platter. On this band are recorded 1000 pulses. A

pickup head that resembles the tape head used in a cassette deck senses the magnetic pulses as the platter ro- tates. The output signal frequency from this pickup at 331/3 rpm is approximately 500 Hz. It is compared with a

similar reference frequency derived from the crystal oscillator after frequency division. Any error between the two signals causes a correcting signal to be generated for the motor.

Denon claims that the 500 -Hz speed -sensing frequency is approximately five times the frequency typical of most direct -drive turntables. This helps give the Model DP -2500 a

speed stability and freedom from overshoot that surpass the performance of other direct -drive turntables.

The neon lamp that illuminates the stroboscope pattern is driven by a signal derived from the quartz oscillator. Hence, a single stroboscope pattern is used for both speeds. The pattern is

stationary during momentary shifts in

line -power frequency and phase, which can cause most stroboscope patterns to waver even when platter speed is constant.

The tonearm consists of an S-

shaped aluminum tube that is balanced by a threaded counterweight on which the tracking -force scale is lo-

cated. After the tonearm is balanced, the scale is set to zero and the entire weight is rotated to align the desired force calibration (0 to 2.5 grams in

0.1 -gram increments) with a reference mark on the tonearm's tube. Antiskat- ing force can be adjusted while a record is being played. The cueing lever for the tonearm is viscous damped.

Tonearm height is adjustable to

accommodate different cartridge dimensions, while remaining parallel to

the turntable.

Laboratory Measurements. Al-

though no stylus -positioning jig was supplied with the sample record player, the setup directions state that the stylus should be 50 mm from the mounting reference surface at the end of the tonearm for minimum tracking error. When the stylus was positioned as instructed, tracking error was very low, typically less than 0.25°/in. and a

maximum of 0.4°/in. at a 2.5" (63.5 - mm) radius.

Calibration of the tracking -force scale was exact after initial balancing of the tonearm according to instructions. The antiskating force had to be set slightly greater than the tracking force for best correction. In our tests, we used an antiskating force of 2

grams at a 1.5 -gram tracking force. The cueing mechanism allowed the tonearm to drift considerably outward during descent. When the stylus finally contacted the record's surface, about 12 seconds was repeated.

Effective mass of the tonearm was about 20 grams. Capacitance of the tonearm and signal cables was 90 pF to ground in each channel and 1 pF

between channels. Turntable speed was more accu-

rate than our ability to measure. The platter came up to speed in less than a second, which was about the same time it took for the platter speed to sta- bilize when switching from one speed to the other. Dc braking stopped the platter completely within two seconds after the OFF button was operated.

isolation was considerably greater than typical

direct-drive player

Rumble was somewhat lower than we have observed on most direct - drive turntables, measuring -35 dB

unweighted and -64 dB with ARLL weighting. Rumble energy was princi- pally below 5 Hz. The unweighted peak or DIN flutter measured -*0.08% (0.075% wrms JIS). Flutter was mostly below 10Hz.

The extremely compliant base

mounting feet had considerable lateral freedom of movement, making it difficult to measure the isolation from conducted vibration in our usual manner, with vibration applied directly to the feet through small transducers. We determined, however, that the isolation of the Denon mounting system was considerably better than that of the typical direct -drive record player. It

was, in fact, comparable to that of many of the better belt -driven players.

User Comment. Although. the Mod- el DP -2500 is a no -frills record player, devoid of concessions to automatic play, it shares many of the qualities we have found in Denon's top -priced Model DP -6700 player. Specifically, it

is unusually easy to set up. Also, when the tonearm is balanced and the cartridge is positioned according to in-

structions, tracking force is precisely correct and tracking error is at the the- oretical minimum for this size tone - arm.

The fast start and stop action of the turntable will be appreciated by anyone who has used an "automatic" turntable that requires one to wait usually 12 to 15 seconds for the tone - arm to reach its playing position after turn -on or for completely shutting down after a record has been played. With the Model DP -2500, the start-up, speed -change, and shut-off operations are virtually instantaneous, smooth, and silent.

Since we use different test methods than those employed by Denon, we did not make an effort to compare specs. As evidenced by our standard measurements, the Model DP -2500 is

indeed a top -rated performer. The only thing we found not to our

liking was the outward drift of the cueing system during descent of the tone - arm. This was in marked contrast to the virtual perfection of every other aspect of the player's design and performance. Of course, the tonearm can be manually handled at all times, which is no great problem in view of its

excellent finger lift and balance. In all, Denon's DP -2500 is a solidly

built record player of exceptional quality. It operates smoothly, rapidly, and virtually silently. It should also prove to be relatively free of the acoustic - feedback problems that plague many record -playing installations. And as an added fillip, its appearance has all the indications of top quality. CIRCLE NO. 103 ON FREE INFORMATION CARD

APRIL 1979 33


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Step up to excellence. Step up to Series E. Why settle for anything less than excellence. Especially now that it's available at a very affordable price in Series E from Hewlett-Packard-five precision calculators for science, engineering and business starting at just $60* EXCELLENCE BY DESIGN. Experi- ence the HP difference in Series E: a new larger display with commas for easy reading; built-in diagnostic systems that help catch errors; RPN logic for ease -of -use and efficiency; a complete documentation system- Owners' Manual and Applications Books; plus a host of HP extras-low battery warning light, rechargeable batteries, positive feedback keys, sturdy impact -resistant case. In sum -excellence by design.

A SERIES E FOR EVERY NEED. Series E gives you more power and features at a lower price than any comparable calculator HP has ever offered. You'll find them all outstanding values: HP -31E. Scientific. $60* HP -32E. Advanced Scientific with

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Dept. 254J. 1000 N. E. Circle Blvd.. Corvallis. OR 97330

HEWLETT-PACKARD Dept 254J 1000 N.E. Circle Blvd. Corvallis. OR 97330

Please send details on Series El Business Calculators Scientific Calculators

Name

Address

City

State Zip

'Suggested retail price excluding applicable state and local taxes -Continental U.S.A.. Alaska and F awaii. Displays photographed separately to simulate typical appearance. =619/03

i,9


Popular Electronics APRIL 1979

EVENTUALLY, most serious electronics experimenters find a need to

measure the power content of an odd -

shaped waveform. This might occur in

measuring the output of a class -C amplifier, audio, video or noise signals; power supply inverter waveforms; or just plain power supply ripple.

When the time comes, the experimenter will discover that a standard VOM or DVM simply won't provide true rms readings! An rms voltmeter is needed for this purpose. Unfortunately, this is

a rather expensive instrument. With the plans presented here, how-

ever, a true rms voltmeter can be built for only about $30. To fully understand how this is accomplished, let's first examine what rms means.

What Is RMS? Rms values allow the expression of the average power content of an ac waveform whose instan -

APRIL 1979

TRUE RMS VOLTMETER I I 11 f I

3 / . ̀ . , `.

4 a wuu

* ' ° I

ta .17.

I j .

Measures effective ác voltage rather

than the usual average values

BY DANIEL METZGER

laneous power varies from zero (at the zero crossing) to some high value at the voltage peak. In practice, rms means "equivalent to dc." Mathematically, given a voltage and a resistance, power is calculated as P=E2/R.

The "equivalent -to -dc" voltage for a continuously varying ac voltage must be calculated by squaring the voltage at each instant, averaging the infinte number of instantaneous values produced (taking the mean), and then extracting the square root. Hence, the term Root of the Mean of the Square (RMS).

For anything beyond a simple rectangular waveform, this rms technique in- volves calculus. For sine waves only, it

produces ER ms = EPK(SINE)/V = 0.707EPK.

For periodic waveforms that cannot be mathematically expressed, the rms technique requires iterative computer analysis. For completely undefinable

35


RMS VOLTMETER continued

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Fig. 1 Schematic of the voltmeter. The amplified input signal illuminates Il, which causes the resistance of PC1 to change. This brings about imbalance in the bridge circuit and meter goes off null.

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Note - The following are available from M. H. Marks Enterprises. 315 Thornberry Ct.. Pittsburgh. PA 15237: set of two etched and drilled pc hoards at $7.95. postpaid: complete kit of parts including cabinet and hardware at $69.95, postpaid. Pennsylvania residents add 6% sales tax. Allow 4 to 6 weeks for delivery. -



5,

PARTS LIST

CI -0.05-µF, 500 volt capacitor C2 through C5 - 50-pF trimmer C6 - 0.22-1.1.F Mylar capacitor C7 - 0.022-µF Mylar capacitor C8 - 0.0022-µF capacitor C9 - 220-pF capacitor CI 0 - 20-pF capacitor CI1 -0.I-µF capacitor CI 2 - 10-pF capacitor Cl3,C 14 - 5-µF, I5 -volt electrolytic CI 5,C I6 - 1000-µF. 35 -volt electrolytic CI 7.0 18 - 100-11F, 25 -volt electrolytic C 19 - 330-pF capacitor DI thru D4. D9 - I N914 D5 thru D8 - I N4002 Fl - I/8 -ampere slow -blow fuse

11 - #47 pilot lamp ICI -LM318opamp 11,12 - Five -way binding posts, one red (11),

one black (J2) LEDI ,LED2 - Light emitting diode M I - I(X)-0-100-µA meter PCI -See text Q 1 ,Q2 - 2N38I9,MPF102, or similar Q3,Q7 - T1P29 or similar Q4,Q8 - TIP30 or similar Q5.Q6 - Any small -signal silicon transistor R1,R3,R9- I-megohm, 1%, I watt resistor R2,R10- 100 -ohm, I% resistor R4 - 1000 -ohm, 1% resistor R5 - I-megohm, I% resistor (try for 990k) R6 - 10.00(1 -ohm, 1% resistor R7 - 909,000 -ohm. I% resistor (try for 9(01k)

R8 - 100,000 -ohm, 1% resistor R I 1 - 10 -ohm. I% resistor R 12 - I -ohm, I% resistor R I3,R 14,R48 - 100,000 -ohm resistor R I6 - 82 -ohm resistor R 18 - 68(4) -ohm resistor R20,R21 - 10 -ohm resistor R22.R23 - 100 -ohm resistor R24,R25 - 22(X) -ohm resistor R26,R27 - 33 -ohm, I -watt resistor R28,R29 - 4.7 -ohm resistor R30.R31 ,R32.R46,R47 - 10,(40) -ohm resistor R33 - I 800 -ohm resistor R34 - 3300 -ohm resistor R35 - 18,(X)0 -ohm resistor R36 - 8200 -ohm. t/ -watt resistor R37,R38 - 2700 -ohm 5% resistor R39.R49 - 7500 -ohm 5% resistor R40.R41 - 680 -ohm resistor R42.R43.R44.R45 - 1000 -ohm resistor R 15 - 50.000 -ohm linear -taper potentiometer R17 - 10(0 -ohm linear -taper potentiometer

(see text) R 19 - 10.000 -ohm. trimmer pot SI - Dpdt center -off toggle switch S2 -8 -position, 2 -pole rotary switch S3 - Dpdt switch TI - 36-V CT. 0.1-A transformer (Stancor

8611 or similar) Misc. - Suitable enclosure, dial plate and

knob for R 17, pointer knobs (2). press -on type, mounting hardware. etc.

waveforms such as noise, however, we have to go back to the rms voltmeter.

This may be a good place to observe that the time-honored VOM and most DVMs actually respond to average voltage (not rms) on their ac scales. The average value of one half -cycle of a sine wave is 0.637 of its peak value, or 0.901 of its rms value.

The meter scales are calibrated in

rms, but this calibration is valid for sine waves only. VTVMs and FET meters generally respond to peak voltages on their ac ranges. Again, the meter scales are calibrated for rms readout cn sine waves only. Consequently, a VOM or VTVM can display different and incorrect conclusions about a 25% duty cycle waveform, as illustrated in boxed section below right. Interestingly, most VOMs err in one direction on non -sine waves, while VTVMs err in the other.

The majority of true rms meters operate by electronically squaring and averaging the input signal, or by taking the log of the signal, doubling it, then taking the antilog. Building such a meter is best avoided because of its circuit complexity. The meter discussed here takes the direct approach of amplifying the input waveform and using its large signal to turn on a conventional incandescent lamp. The brilliance of the lamp is

sensed by a photocell so that compari- sons between ac and equivalent dc voltages can be made. In operation, the amplifier gain is adjusted until the lamp reaches a predetermined brightness, and the rms voltage is then read off a

calibrated "gain" control.

Circuit Description. As shown in

Fig. 1, resistors R1 through R9 provide voltage divisions by progressive factors of ten while maintaining a 1-megohm in-

put resistance. Capacitors C2 through C10 provide identical division ratios at

high frequencies while maintaining an

input capacitance of 20 pF. Without these capacitors, the reactance of any stray wiring capacitance would completely swamp the resistive dividers above approximately 50 kHz, resulting in false division ratios. Resistors R10 through R12 are used in the measurement of current.

Source follower Q1 provides an almost infinite input impedance for the amplifier, while FET 02 provides com- pensation for variations in Qí source voltage with temperature. Both Q1 and 02 should be well matched-zero volts between their sources with the input grounded and control R15 (zERo) near Seraninala al f

the center of its rotation. Also, the transistor cases should be thermally bond- ed.

Op amp ICI has a gain between 10

and 100, depending on the setting of the CAL (R19) and NULL (R17) controls. Ca- pacitor C12 compensates for stray capacitance in the R16-R17leg, and is selected for good high -frequency re-

sponse. Components R20, R21 and Ci / are required to prevent high -frequency oscillation via power supply coupling. A complementery symmetry voltage follower (Q3 and Q4) provides the high current required by lamp 11.

The sensitive surface of photoresis- tive cell PC1 is butted to the lamp and secured in place with opaque heat - shrink tubing. The photocell forms one arm of a Wheatstone bridge, with R30 - R32 as the other arms. At one particular

VTVM AND VOM ERRORS

For sine waves:

VpK = 1.414VRMs = 1.569VAVG

VRMS = 0.707VpK = 1.110VAVG VAVG = 0.637VpK = 0.901 VRMS

VOMs read 1.110VAVG VTVMs read 0.707VPK

For this rectangular Wave:

+4V

OV

-4V

1 I.

ACROSS r

1 2 3 4

V4 DUTY CYCLE

PINST = E2/R = 42/1 = 16 W

PAVG=16/4=4W ERMs= 15r1=V4 x 1 =2.00V VOM reads:

1.110 x VAVG = 1.110 x 1/4 x 4

= 1.11 V or 2.00 VRMS

VTVM reads:

0.707 x VpK = 0.707 x 4

=2.83Vor2.00VRMs _..

APRIL 1979 37


RMS VOLTMETER continued

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CI6 -D7- =- D8 -.

De R44

C17

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CI8 R45

R46 -L-{ + `

R4I

-R47-

Fig. 2. Actual -size foil pattern for main pc board is at top, component installation immediately above.

Fig. 3. Components for attenuator can be mounted on board similar to that at left. Only four sections are used in this case.

lamp intensity, the cell resistance will equal 10,000 ohms and meter M1 will indicate zero. For unbalance currents of about 251.LA, D1 and D2 will begin to conduct, shunting the meter with R33. This makes it easier to find the null by reducing the meter sensitivity for off -null settings. The meter can be switched to zero out dc voltage at the amplifier output when the input is grounded.

In the' prótotype, balance was achieved with 2 volts rms (or dc) across the lamp. For sharply peaked waveforms, it is possible that the peak voltage might exceed the approximately 10 -volt limit of the amplifier resulting in distortion of the waveform. Diodes D3 and D4 detect such peaks slightly before the threshold of distortion, causing the front panel positive (LED1) or negative (LED2) overpeák indicators to glow.

The power supplies are well filtered by the emitter follower action of 07 and 08. Regulation is not required because the differential amplifier and bridge circuits remain balanced in spite of power supply voltage variations.

Construction. Few of the components are critical and substitutions are possible. The NULL potentiometer (R17) should be of the highest quality since accuracy of the instrument depends on reading its angular position. Resistors R1 through FR/2 directly affect the accuracy and should be held to ±1%. For the voltage dividers, it is the resistance ratio that is important. Ceramic trimmer capacitors hold their values better than compression types and are recommended for C2 through C5. Transistors 03 and 04 may dissipate as much as 2

watts and must have heat sinks. Using an LM318 for IC1 results in a

400 -kHz bandwidth. A p.A741 reduces the bandwidth to about 20 kHz. Any pho- toresistive cell having a resistance of 10,000 ohms when illuminated by a #47 lamp with 1.5 to 2.5 volts dc applied to it will work for PC1.

The bulk of the circuit can be assembled on a pc board using the foil pattern and component layout shown in Fig. 2. The front-end attenuator can be built up on a small pc board like that shown in Fig. 3. Fixed and trimmer capacitors are mounted on the foil side and the resistors on the other. This board supports the first four attenuator elements. (Two sections on this small board will be unoccupied.) Once the components are mounted on the board, the pc assembly can be wired to the appropriate lugs on S2 with short lengths of hookup wire.



.f'

6 -

4

9

People t using our n - .. tape care kit should have

their heads examined. After every ten hours of recording your tape deck. keep even areas you can't see

or twenty hours of play back, you So at Maxell, we've developed a spotless. All of which means you'll be

should spend a few minutes cleaning tape care kit tohelp you gét the getting maximum performance out of

your tape heads. cleanest possible sound out of your your machine. Year after year.

Because in that period of time recordings. And it that doesn't sound like a

enough dust and residue accumulate In addition to liquid head cleaner, good idea, maybe you 'need

on your tape heads to significantly it has special curved probes; swabs, to have more than your tape heads

affect the sound that comes out of a brush and a mirror to help you examined.

maxell II1111111111I1111 I I I I I I I III IIIIINIIIIIIIII I I I I I I I I I I i 1111111111111111111111111111111111111111111111111111111111111111u11111111111111111111111111111111111111111111 Nkrxell COrocloi0o ok Amenco. 60Oxlord ]rive, AHxxc-hie, N. 107074



yh414 . .' i / : f..

Photo shows how author mounted components in prototype Of voltmeter.

(A)

Fig. 4. RMs value of sine wave can be cale aluted as described in test using diagrams shown here.

The four remaining attenuator sections are resistors that can be mounted directly on S2.

As shown in the photograph, on the front panel are the meter, two overpeak LED's, R17 (NULL), R15 (zERO), S3 (NULL/ZERO), S1 (AC, DC POWER ON -

OFF), S2 (RANGE) and input jacks J1 and J2.

These components can be mounted as desired on the front panel, leaving enough room around R17 to accommodate a calibrated dial plate. Press -on type can be used to identify controls.

Calibration. Set the NULL control (R17) to its minimum resistance. With 40

P=I2 Rs

(B)

40,

s

L P=E2/RP

J

MN«

S3 at ZERO, connect J1 to J2 and adjust R15 (ZERO) for no meter deflection (center zero).

Set S2 to the x 1V position and S3 to NULL. Apply an accurate 1 -volt dc between J1 and J2 (positive to J1) and adjust the pc board mounted R19 for a zero meter indication.

Mark the NULL dial plate with' a 1, then apply 2, 3, etc., up to 11 volts dc, zeroing the meter with the NULL control and marking the dial as you go. If desired, you can apply a 60 -Hz sine wave of known rms value to verify the "equivalent -to -dc' function.

The S2 trimmer capacitors can be adjusted with the aid of an audio generator.

Null the meter to read a 60 -Hz sine wave someplace on the x.1 range.

Without changing the generator output level, raise the frequency to 50 kHz and adjust C5 for a null at the same spot on the dial. Repeat this for C4, C3 and C2 on their ranges. Alternately, the trimmer capacitors can be adjusted for the cleanest 10 -kHz square -wave response with a scope probe across 11.

Use. Here are some guidelines for using the rms meter.

When there is an ac or combined ac and do voltage across an unvarying (pure) resistance, the rms value of the voltage can be used to compute the average power in the resistance by the equation PAVG = ERMs2/R.

Similarly, if the rms current through an unchanging resistance is known, then PAVG = IRMS2 R.

Note that unlike many rms meters, the meter described in this article can indicate the rms value of a waveform having a dc component. This dc component cannot be simply added to the rms value of the ac component to obtain the rms value of the total waveform. For sine - wave ac components, the rms value can be calculated as illustrated in Fig. 4. For other waveforms, it's either calculus or the dc -coupled rms meter.

An rms measurement cannot be applied to the calculation of power where the load impedance is partly reactive. However, if the numerical value of the resistive part of the load can be determined, true power can be calculated as shown in Fig. B, since the reactive portion consumes no power.

The rms measurement is also not appropriate for calculating the average power delivered to devices having changing ohmic resistance. Examples of such devices are diodes, SCRs, switching transistors and the plate or collector of a class -C amplifier.

For such devices, measure the average voltage and current for the device and calculate: PAVG = IAVGEAVG-

If current flows always in one direction, a VOM on the dc range can be used. If ac is involved, you must use a meter that measures the average absolute (without regard to sign) value of voltage and current.

A VOM or average -reading DVM on the ac range fills this function if the readings are multiplied by 0.901 to change the rms calibration to average calibration. Be wary of such meters on the ac ranges since many of them have upper frequency limits below 1 kHz.

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CMI 1979230R J AmericanRadioHistory.Com

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APRIL 1979 45


lntroduCng the system that can .tape itself.

Tune!tself,1Jl:byItselt-For úpt a week. 5

Technics Ou.arra Sy,4 MN! Stone Twee 5T9030

la..Y B :... i o

Technics, _ torran M1r!aa.m. V+ o-WM - s

r?

Ùp to now using a tape deck to record Tchcikovsky's 4th at 4 PM on one sto'icn and Beethoven 'S 5th at 5 PM or another was easy. As long as you were hóme Now -

Technics makes ilt jest as easy when you're not, with the' ST -9028 quartz synthesizer FM stereo tuner and its '1 matching SH-90138 microprocessor.

When used with the ST -9038, the SH-9038 microprocessor can be programmed to tune eight =M stations in any order, at aiv t me, on any day for one week. In

fact, the SH-9038 can be programmed to renember 32 irdividual steps. Starring with the day of the week, the time, the FM station cnd AC line on/off.

All you do is sin -ply select the write ' mode and :he

-7SH-90.3.8s computerized memory does the rest.Then select the "read"' n- ode for a.reádout of the -programs you hcve selected.You can also override your preseledted program by swikh ng to the manual mode. What's-m,ose, the SH-9038 can be programmed to turn on or off th-ee other components in addition to the ST9031 tuner.

T-a's what the SH-9938 microprocessor can do. What the ST -9038 quartz synthesizer tuner min do, is juft as -impressive. Uilike conventioncl tuners which use a series of variable capacitors to tu.ie in FM frequencies,

thl.ST-90218 uses tie qúartz synthesizer tuning system. With this system the quartz crystal, one óf the world's mostaxc-ate reference -devices, becomes the reference far the local oscillator frequency and the broadcast -

frequency_ The results: Only the frequencies on which a '

broadcas- signal might exist can be received. At precise@y.

spaced 200 kHz steps. And that mews you dón't have to wormy about drift or rrmisallignment due to temperature, tine or mistuning. - _

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CIRCIEhO. 53 ON FREE INFORMATION CARD


Although transmission -line transformers are widely used ín front

ends of television receivers, there is not much information available about what they are and how they work. It is often assumed that they are just another ordinary transformer that uses a fancy high -frequency ferrite to obtain the desired results. In reality, the only thing in

common between transmission -line and conventional transformers is the name. Their operating principles are totally dif-

ferent. In this article, we will explore what a transmission -line transformer is

and how it works. But first let us see how

it differs from conventional transformers.

How It Differs. In a conventional transformer, an alternating current in the primary continuously changes the amount of flux in the core, which, in turn, sets up a voltage in the secondary. Disregarding losses, since the amount of flux cuts every turn of both the primary and the secondary, the voltage ratio is

directly proportional to the ratio of the turns in the windings. Also, since the action of the conventional transformer depends on the flux generated in the core, the bandwidth and efficiency depend entirely on the core material.

Normal iron cores are useful at frequencies up to a few hundred hertz. Al- though there are ferrite cores used in the megahertz range, their permeability and efficiency drop off fairly rapidly with in-

creasing frequency. Another factor that comes into play at high frequencies is

that the capacitance between the turns of the windings also limits the useful- ness of the conventional transformer at megahertz frequencies.

It is useful at this point to examine a

few conventional transformers to corn -

APRIL 1979

pare them to the transmission -line transformer we are talking about here.

A simple step-up transformer with a

center -tapped secondary is shown in

Fig. 1A. Three things are obtained with such a transformer: a step up in voltage at its output, isolation between its primary and secondary, and a secondary that is symmetrical about its center tap. Here we are mainly concerned with the voltage ratio. Another parameter that should be mentioned because it is very important in transmission -line transformers is the impedance ratio.

ISS1, 114 US ade

from

t

be m coaxial transformers can

coreess tra transmission

line

Another transformer that is very similar to that shown in Fig. 1A, except that the primary and part of the secondary are a common winding, is shown in Fig.

1 B. This autotransformer does the same job as the previous transformer, except that there is no isolation between the primary and secondary windings.

Finally, in Fig. 10 is a very simple 1:1

isolation transformer. In this case, the impedance, turns and voltage ratios are

all 1:1. The only purpose of such a transformer is to provide isolation between the primary and secondary windings.

Suppose that the primary of the transformer shown in Fig. 1A is rated 6 volts and 1 ampere (6 watts). Since we cannot obtain something for nothing, the output, even at 100% efficiency, can never be more than 6 watts. Hence, if

the secondary potential is 12 volts, the secondary current can be no greater than 0.5 ampere.

By Ohm's Law, impedance is equal to the voltage divided by the current (Z = E/I), where E and I can be ac terms. Therefore, the impedance of the primary in our example is 6 volts/1 ampere, or 6

ohms, while the impedance of the secondary is 12 volts/0.5 ampere, or 24

ohms. Hence, even though the turns and voltage ratios are 1:2, the impedance ratio in our example is 1:4. (The impedance ratio is actually the square of the turns ratio.)

BY ROY HARTKOPF Although the schematic symbols

shown in Fig. 1B and Fig. 10 can be and

often are used for transmission -line transformers, this is where the resemblance between the conventional and

transmission -line transformers ends. The first and perhaps most striking dif-

ference between the two is that with the transmission -line transformer, the core material is relatively unimportant. In-

stead of limiting the high -frequency re-

sponse, the only effect it has is to extend the low -frequency response.

As far as high -frequency response is

concerned, the core just does not mat-

ter. It could be made out of hard candy and the transformer would still work. A

second very important difference is concerned with the number of turns. With the transmission -line transformer, the

number of turns has nothing to do with

(A) - (8) (C)

Fig. 1. Three basic transformers: (A) step-up; (B) autotransforrner; (C) isolation.

47


the impedance. Finally, the pains taken to minimize capacitance in a conventional transformer are unnecessary in the transmission -line transformer. The transmission -line transformer uses the capacitance between its windings. In fact, this capacitance is often made as large as possible by twisting together the wires that make up the transmission - line transformer.

Technical Details. The transmission -line transformer is simply a length of transmission line. It is a pair of conductors that are either parallel to each other, twisted together, or arranged coaxially. Of importance is the spacing between the conductors, which must be constant throughout the line's length.

Each conductor in the transmission - line transformer has an inherent inductance. Also, between the wires of a conductor pair, there is an inherent capacitance. It is this combination of continuous inductance and capacitance that gives the transmission line its characteristic impedance. Any type of line can he used for a transmission -line transformer, but if a line is wound on a toroid, parallel or twisted lines are most often used because they are easy to handle and do not get pulled out of shape.

Examples of the characteristic imped- ances one can expect from various types of lines are as follows: No. 23 PVC -insulated hookup wire twisted at about one turn/inch yields about 150 ohms; 0.040" enamelled wire with about eight twists/inch yields about 25 ohms; and 0.040" enamelled wires wound side by side, with the turns kept as close together as possible, works out to between 50 and 70 ohms.

The essential condition for the proper operation of a transmission line is that the currents flowing in the two conductors be equal and opposite. Anything that causes an unbalanced current flow will prevent the line from operating properly. Suppose, for example, that a coaxial transmission line is very short and has one leg grounded at each end, as shown in Fig. 2. It is quite possible that there could he a ground current, Iq, flowing through the ground leg in addition to transmission -line current. There are, in fact, many ways in which a short transmission line can have unbalanced currents flowing through its conductors, all of which defeat the effect of the line.

Suppose the short transmission line shown in Fig. 2 were wound to form an inductor, as shown in Fig. 3A. (Its schematic representation is shown in Fig.

Fig: 2. Current ,flow in a short piece of coax line grounded at each end.

001 -.\--71

(B) -

Fig. 3. Coax line wound to form an inductor (A) and its schematic (B).

Fig. 4. The 4:1 balun is similar to autotransformer shown in Fig. 1B.

.Q4400_ b000 00000\

. s

Fig. 5. A transmission -line transformer for interstage

-coupling with do isolation.

3B.) Even though one leg is still grounded at each end, the ground current will be impeded by inductive reactance. The transmission -line currents, however, would not be affected here because they are equal and opposite at every point along the line, thus neutralizing the inductive effect of the coil. The actual line length can be short as 1/50 -wavelength so no significant phase shift takes place.

If the transmission line were now wound on a ferrite rod or, better yet, a toroid core, it would be even more effective and would produce a higher degree of isolation. As the frequency increases, less inductance would be required to obtain the same isolation effect. Even if the core material is useless at very high frequencies, the isolating effect would still remain.

The autotransformer shown in Fig. 1B has a voltage ratio of 2:1 and an impedance ratio of 4:1. Exactly the same ratios can he obtained with a transmission -line transformer. The principle involved can be readily seen with a coaxial transmission line, as shown in Fig. 4. This is the well-known 4:1 balun (balanced -to - unbalanced) transmission -line transformer. The schematic symbol for the balun transformer would be the same as for the autotransformer of Fig. 1B.

In Fig. 4, ignoring losses, if a voltage is supplied between points Al and B1, it will appear at points A2 and B2. With point B2 connected to point Al, twice the input voltage would appear across output points B1 and A2. This means that the output impedance would be four times the input impedance and the output would he symmetrical about the Al/ B2 junction. In practice, the Al /B2 junction would be connected to the shield of the main coaxial transmission line and would generally be grounded.

There must he a very high impedance to out -of -balance currents between Al and A2, isolating the two ends from each other. As a rule -of -thumb, this could be at least 50 times the characteristic impedance of the line -2500 ohms for a 50 -ohm line. Winding the cable around a toroid is an effective way of getting the required impedance. A special case is the )/-wave balun, where isolation is provided by the )/-wave effect. How- ever, this is effective only at one frequency, and cannot provide a broad- band transformer.

Making a Transformer. Now that you know what a transmission -line transformer is and how it works, let us proceed to make a vhf power transform -



er using a core of audio -frequency material. Just about any type of toroid-ferrite or, better still, one made from flat strip iron rolled up in a coil, such as the type used in dc -to -dc converters-will do.

Wind two lengths of 0.040" enamelled wire onto the toroid. Keep the wires parallel to each other and make each turn touch the previous turn. Do not attempt to crowd too many turns on the toroid. The object is to wind only as many turns on the toroid in a single layer without having the conductors cross each other.

Bear in mind that many toroids have sharp edges and that even ferrite material is often conductive. If the edges cut into the insulation, the wire windings can be short-circuited. If the transformer does not operate as expected, short-cir- cuiting will be the most probable cause since, practically speaking, there is

nothing else that can really go wrong with the transformer. After winding your transformer, use an ohmmeter to test the insulation between each conductor and the core and between windings.

The basic transmission -line transformer just fabricated will yield a 1:1

impedance ratio and complete isolation so that it can be used as a balanced -to - unbalanced or, for that matter, any other type of configuration. If we need a 4:1

balun, it is necessary only to connect the ends of the conductors as shown in Fig.

4, without altering the winding. When necessary, as when using a

transmission -line transformer for inter - stage coupling, dc isolation can be obtained by using three transformers, as shown in Fig. 5. Remember that the core is there only to prevent out -of -balance currents. Therefore, if the wire size is

small enough and the toroid core is large enough, it is possible to wind all three transformer windings on the same core.

In Conclusion. There is one basic. limitation concerning transmission -line transformers. This is that the ratios ob- tainable are limited to 1:1 and 2:1, and multiples of 2:1 if two or more transformers are used. Also, it can be difficult to

obtain the required impedance, particularly with a twisted -pair line.

If you want to build a wideband amplifier and must match, say, a 12 -ohm transistor to a 50 -ohm output, or make a

balanced modulator, or provide really good isolation in a noise bridge, or make a balun transformer for a high -power transmitter, the transmission -line transformer is the way to go. The transmission -line transformer offers a great opportunity for experimenting.

APRIL 1979

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49


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CIRCLE NO. -45 ON FREE INFORMATION CARD .


THE "SILENCER" dynamic noise fil-

ter described here can eliminate tape hiss, record -surface noise, and at-

mospheric radio noise. Consequently, it

is an ideal add-on device for stereo hi-fi

systems. Moreover, it does not require

encoding and decoding. The device is essentially a voltage -

controlled low-pass filter whose cutoff or

break frequency is continually changing to accommodate program material and

shut out any detracting noise. It only filters when noise and hiss are audible, when program material is at a low level

or absent. The phenomenon of masking is utilized. That is, high-level signals mask noise that would be objectionable if program material level were low.

When such masking occurs, the whole

signal is passed. When there is no

masking by program material, however, the filter extends the bandwidth only as

far as required by the music. Beyond

this, the high -frequency noise is at-

tenuated. The frequency at which the fil-

ter begins rolling off to attenuate high -frequency noise is called the "break frequency."

About The Circuit. The silencer circuit constantly analyzes incoming signals for amplitude, frequency, and persistence. These factors determine the bandwidth at any instant, as well as how quickly the variable low-pass filter changes. Attack and release times vary with the music, thus eliminating a "pump and wheeze" effect of noise modulation.

The device has a continuously variable threshold control, with front -panel LEDs calibrated to indicate "Low;"'Mid," and "High" break frequencies. The fil-

ter's break frequencies vary between 1.5 and 20 kHz with a roll -off slope of 9

dB/octave (maximum). The Silencer is a

single -ended stereo device, making it

ideal for use with tapes, records, and tuners for playback and record purposes.

The unit connects either in the auxili-

APRIL 1979

BY COLLEEN McNEICE AND ROGER COTA

Build a DYNAMIC AUDIO NOISE FILTER

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radio, tape and

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51


RIGHT INPUT

LEFT INPUT

ary mode or in the tape loop of your audio amplifier. On the back panel are IN

and OUT jacks for the tape loop; the front panel also has a TAPE monitor button, and a system DEFEAT.

The block diagram of Fig. 1 shows the functions of the dynamic noise filter. The voltage -controlled low-pass filter is com- posed of IC1A and IC18, as shown in the schematic of Fig. 2. (The components to the left of the dashed line make up one stereo channel; only one is shown in the schematic for clarity.) The gain of op amp IC1A is approximately R3/R5. At low frequencies, the capaci- tive reactance of capacitors C4 and C5 is very high, making the output of 1C18 look like a low impedance source. The gain of /CIA is then:

A = R3/R5 = 10,000 ohms/ 1000 ohms = 10

At higher frequencies, however, the impedance of C4 and C5 decreases; IC18 generates an output and boot- straps R5. This bootstrapping effect causes R5 to look larger. Therefore, gain A becomes smaller and the filter at- tenuates the high -frequency energy.

To vary the breakpoint of the filter, FET Q1 has the ability to shunt the signal at the non -inverting input of 1C18 to ground. Figure 3A shows the filter with the FET open and the high frequencies attenuated, while 3B illustrates the filter's action with the FET shorting the signal to ground. The control signal applied at the gate of the FET allows the bandwidth of the low-pass filter to be self-adjusting for any frequency. This allows high -frequency signals and subtle harmonics of fundamental bass frequencies to be passed, while unmasked noise is attenuated.

OUTPUT

DISPLAY

DRIVER 1~

OUTPUT

The circuits represented by the shad- ed blocks of Fig. 1 are the dynamic analytical controls. They automatically judge the program material, adjust the bandwidth to accommodate it, and change the attack and release times to maximize the masking effect and minimize noise modulation. The control signal is applied to the gate of Q1. It's determined by the (1) spectral content, (2) amplitude, and (3) persistence of the incoming signal.

The spectral content is sensed by the high pass weighting filter, a network made up by R8, R29, R30, R31, C6, C17, and IC2A. This network is driven by the output of 1C1B, which actually determines the quiescent operating point of the low-pass filter. Amplitude is determined by threshold control, R27, a 100K -ohm front -panel potentiometer. This pot sets the voltage divider for the positive input to IC2A, and the dc level for IC2A's output. The dc output level determines the quiescent operating point of the FET. The dynamic operation

A 20 5K

9dB/OCTAVE SLOPE

FREQUENCY (HERTZ)

DISPLAY

Fig.1. Block diagram shows how input signals are processed to generate a control signal. This signal governs filter's break frequencies to pass music but attenuate noise.

of the FET is adjusted by the ac control signal, allowing it to follow the program material. The ac component of IC2A's output is determined by sensing the signal's amplitude on the output of 1C1B.

The persistence log amp is formed by R33, D2, and C20. It checks the correla- tion coefficient of the signal, and adjusts the attack and release time of the low- pass filter to minimize any noise modulation problems. Variable attack and release times allow for the most effective masking of the noise.

The anti -log amplifier IC28 also senses the control voltage output of IC2A. This signal is then rectified and filtered by D4 and C21, and is then used to drive threshold comparators IC2C and IC20. These amps drive the logic network of D5, D6, and D7, which drives the display. The 10K -ohm trimpot, R37, is used to calibrate the LEDs. The red LED indicates a break frequency of 1.5 kHz, the yellow, a break frequency between 1.5 and 10 kHz, and the green that the filter is opening up above 10 kHz.

Fig. 3. Frequency response of a low-pass filter when its break frequency is 1500 Hz (top) and 20,000 Hz (bottom).

20K

9dB/OCTAVE SLOPE

e 20 1.5K

FREQUENCY (HERTZ) 20K



PARTS LIST

CI, C3, C9, Cl!. C21 -1-µF 50 -volt axial -

lead electrolytic capacitors C2, CI 0-680-pF disk ceramic capacitors The following are 100 -volt Mylar capacitors: C4, C5, C12, C13 -.022-µF C6, C14, C 17-.001- µ F

C7, C15, C20 -.1-µF C8, C!6 -,01-µF CI8, C22, C23, C24 -1000-µF 35 -volt radi-

al -lead electrolytic DI -33 -volt Zener diode D2 through D7-IN914 signal diode

D8 through DI I-IN4002 rectifier FI -t/2 -ampere fuse

ICI , 1C2 -µA4136 quad op amp (Fairchild) 11 -18 -RCA phono jacks LED I -Red (Fairchild FLV 110 or equiva-

lent) LED2-Yellow (Fairchild FLV 410 or equiva-

lent) LED3-Green (Fairchild FLV 310 or equiv.) Ql, Q2 -Matched pair of 2N5458 JFETs.

The following are t/ -watt, 5% tolerance resis-

tors: RI. R 13, R26-47,000 ohms R2, R I4, R35, R43, R44-4700 ohms R3, R15, R33, R38-10,000 ohms R4, R 16-100 ohms R5, R 17- 1000 ohms R6, R18-39,000 ohms R7, R19, R45, R46-2200 ohms R8, R20, R29-15,000 ohms R9, R21-11,000 ohms RIO, R22, R36, R39, R41-100,000 ohms RI 1 , R 12, R23, R24, R34-1 megohm R25-22,000 ohms R28, R32-470,000 ohms R30-680,000 ohms R31-130,000 ohms R40. R42-27,000 ohms

Other resistors and controls: R27- 100,000 -ohm potentiometer with switch

(CTS FR-GC-XM 450 or similar) R37-10,000 ohm thumbwheel trimpot R47, R48-- 10 ohms, th watt, 5% tolerance

resistor S I , S2-DPDT switches S3 -I I0 -V,2 -A switch (part of R27) TI -22 -volt center -tapped, 50-mA transform-

er Misc-Ac line cord, knob for threshold pot,

buttons for switches, suitable enclosure, hardware,hookup wire, solder, etc.

Note -The following items are available' from Logical Systems, 3314 "H" St., Vancou- ver, WA 98663 (Tel. 206-694-7905): Com- plete 318 Silencer kit, including 6063 ex-

truded aluminum chassis and hand -finished black walnut end pieces, $129.00. Also available separately: Etched and drilled circuit board, $15.00; individually tested and

matched 2N5458 FETs, $3.50. Washington state residents please add 5% sales tax.

APRIL 1979

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Fig. 4. Actual -size etching and dril6ling guide for the "Silencer." Board is shown at (A); parts placement at (B).

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OPERATING SPECIFICATIONS-"SILENCER"

Ñ

Construction. This unit is most easily

constructed using a printed -circuit board. Complete etching and drilling guides are shown in Fig.4A, with the component guide shown in Fig. 4B. Pro-

per orientation of parts is very important. Take careful note of how FETs 01 and

02 are mounted as well as op amps, di-

odes, and electrolytic capacitors. Also

observe that the dynamic characteristics of the FETs must be matched. More- over, when choosing op amps, it is im-

portant to make sure that the one chosen for the detection circuit, 1C2, has an

open -loop gain of at least 50 dB at 10

kHz. Op amps in the parts section were chosen for their excellent noise figures.

The unit is designed to fit into a cus-

tom aluminum extrusion, held by the

J eight screws in the wood ends. Any suitable enclosure will work, however. The circuit board itself measures 6" x 9".

The RCA phone jacks, front -panel switches, and threshold pot are circuit - board mounted for ease of construction and minimum noise. LEDs may be cir-

cuit -board mounted or attached to your

Hiss Reduction:

Max. Filter Slope:

Frequency Response:

Minimum Bandwidth: (Filter Closed)

Dynamic Range:

S/N Ratio:

THD:

IM Distortion:

Rated Output:

Max. Output:

Input Impedance:

Output Impedance:

Power requirements:

15 dB at 10,000 Hz

9 dB/octave

20 to 20,000 Hz -±0.5 dB

1500 Hz

Output noise greater than 100 dB below max. output, 20 to 20,000 Hz

Better than 85 dB below 2 V ac output 20 to 20,000 Hz

Less than 0.1%, at rated output, 20

to 20,000 Hz.

Less than 0.01% at rated output 60/7000 Hz mixed 4:1; typically less than

0.005%

2 V ac into 10,000 ohms

10 V ac into 10,000 ohms

47,000 ohms, single ended

100 ohms

110/120 V, ac 50/60 Hz, 8 W

Note: All measurements made with filter bandwidth open maximum except where specified.

(This is the worst -case condition.)

front panel and then wired. If you choose not to use the furnished printed -circuit guides, make sure that the power supply is as far away as possible from the rest

of the circuit to eliminate stray hum.

Calibration. Calibration should be

done before you fully enclose the unit. To calibrate, connect the noise filter into

your amplifier's or receiver's auxiliary or

tape input. Find a low-level noise

source-an erased magnetic tape would be ideal. If you don't have tape facilities you may use the inside groove of an LP

record. Increase the amplifier's gain so

you can hear the noise very well.

Start with the Silencer's threshold pot turned fully counter -clockwise and

slowly turn the control knob clockwise. You will hear the noise change character and become more objectionable. Re-

turn to the position where the noise -con-

tent change just begins (listen several times so you will be able to identify this

point). With the threshold knob in this

position, adjust R37, the thumbwheel trimpot, so that the red LED lights. You should adjust the pot so that it is at the

point where only a slight adjustment will

cause the yellow LED to light. In conclusion, this easy -to -build

noise -reduction system will be a helpful and versatile addition to any stereo hi-fi

system, cleaning up signals from any

source. O

APRIL 1979 55


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I EXPERIMENTS IN . , ',Atli. :..,' ,+

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Basic Primer By M. Waite & M. Pardee

Covers BASIC fundamentals, program control, organization, functions & variations. With a game program & data on numbering systems & ASCII character codes. 192 pgs. #21586... $8.95

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Examines assembly -language programming of 8080, MC6800 & MCS6502 models. Ex- plains concepts, operation & architecture. With precanned operations. 256 pgs. #21459... $8.95

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Introductory Experiments in Digital Electronics and 8080A

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POPULAR ELECTRONICS


el

Construction. The Morse -A -Word is

most easily assembled using printed circuit techniques. Three pc boards are re-

quired-a main circuit board, display board, and a power supply board. The parts placement guide for the main circuit board appears in Fig. 5. Etching and

drilling guides are shown in Fig. 6. Simi- larly, etching and drilling guides for the

double -sided display board are shown in

Fig. 7. This board's parts placement guide appears in Fig. 8. Finally, the etching and drilling and parts placement guides for the power supply board appear in Figs. 9 and 10.

When soldering components to circuit board foils, use a low -wattage, fine - tipped soldering pencil and fine solder. Be sure to employ the minimum amount of heat and solder, consistent with good connections, and take care not to inad- vertently create solder bridges between adjacent foils. The use of IC sockets or Molex Soldercons is recommended.

Assemble the main pc board first.

TO LED I

ANODE

TO SPEAKER

(HOT)

TO POWER

SUPPLY +8V '

}i1^rDGbc

o

1

BY GEORGE STEBER

PART TWO: Construction,

AI ignment, and Use Start by inserting and soldering the IC

sockets and Molex Soldercons. Install the smallest components next, gradually working up to the larger items. For ex-

ample, start with the 114 -watt resistors, then instalf the diodes, the small capacitors and finally the larger capacitors. Be

sure to observe the polarities of diodes and tantalum and electrolytic capacitors, and the pin basing of transistors and ICs. The board furnished by the kit supplier has olated-through holes so you

need only solder component leads on

the bottom side of the board. Neither the power supply, the display

circuits, the sidetone speaker, jacks, CODE and DAH LEDs or the SPEED con-

trol are mounted on the main pc board. Insulated wire leads of suitable lengths should be soldered to appropriate points on the pc board now for connection to

these components. Wire the display board next, referring

to the parts placement diagram of Fig. 8.

Use Molex Soldercons to mount the dual

TO LED 2 TO SI ANODE

TO POWER SUPPLY GROUND

TO POWER SUPPLY TO +5V R28

DISPLAY BOARD JUMPERS

TO POWER SUPPLY -8.2V

O.R2-p i

4;3°4 - O . _

9

;

O o OO

9(1l 1. t y O A O -puzo

QC270

N MORSEA - WORDIM 0

IC RO

IEE 1785R LED displays. Make sure the

Soldercons are properly aligned before soldering them to the board. This will en-

sure a good fit for the displays. Resis- tors, capacitors and IC sockets or Sol-

dercons for the driver ICs should be in-

stalled and soldered next. The resistors should be mounted in a vertical position. Notice that there are a number of jumper wires to be soldered to this board. These

are used to interconnect the display board and the main circuit board and to

support the display board. The jumpers

should be made of heavy solid wire, about 1" (1.3 cm) long, and bent into "L" shapes so they extend parallel to the

board and point downward. Position the display board perpen-

dicular to the main pc board. Insert. the

jumper wires connected to the display board through the appropriate holes on

the main pc board and push down the

display board until it just touches the

main board. Check the alignment of the

display board and then solder the jump -

TO JI

TO SPEAKER (GROUND)

TO JI a J2 GROUND

-TO J2

Fig. 5. Parts placement guide for the main circuit board.

TO LED I

&LED2 CATHODES

57


0gao48 oa". ° O. .. . nn

00000

ó+

ó: oóoó° 8 °o

o y.m .0 o o 0 00 O -

°+0 O o.°<;-°960° O O q

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.

000°0 00 0

000 00o

O ̀

o' o 0. .o.

o10 00 .

o o

00000o °

0 MORS.E A WORD

0

Fig. 6. Actual -size etching and drilling guides for the double -sided main printed circuit board. 58

POPULAR ELECTRONICS


o

Ill 0000'

o

- FRONT

¡IJI5001'`001000 III 4

ers to the foils on the bottom of the main

pc board. Cut off excess jumper lengths. For proper Morse decoding, the

1702A ROM must be programmed in ac-

cord with Table I. A construction article that appeared in the February 1978 is-

sue of this magazine described a project that allows you to program your own

blank ROMs. Some parts distributors will program the 1702A for you if the

truth table accompanies your order. The

Fig. 9. Actual -size etching and drilling guide for the power

supply board.

DSPLY BOARD

1

0 00J0000

6D1

e a

a

9. 8

sa

-L,- EDI

v

¿DI v

a la

S 18

418

ti

x

>

7

o l)

V 11=

a v L la

Ed I la

La ola

i a 6 a

Fig. 8. Parts placement guide for front side of

display board is above.

0 0 8 o g Fig. 7. Actual -size etching Q and drilling guides for

.0 the double -sided display board are at left.

kit supplier for the Morse -A -Word also

offers a preprogrammed ROM. Install the ICs and the dual -character

IEE 1784R LED displays in their Solder -

cons. Make sure they are correctly ori-

ented and take the usual precautions to

avoid bending the leads or damaging the MOS ROM. It is not necessary to

have a full eight -character display. Those builders with a tight budget, for

example, can install only one dual-

} Ol C2

-

,

R3

cl' + . ,x2

X2

character IEE 1785R LED readout.

However, a minimum of two readouts (four characters) is recommended. If

fewer than four readouts are used, make

sure they are right -justified (installed at

the DIS4, DIS4 and DIS3, etc.) The remaining pc board, that for the

power supply, should now be assem-

bled. You will note that the board has

space for extra components to be used

in another project. These components

APRIL 1979 a


ofessional or not, the Computer; the best books in the fi1

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THE "COMPULATOR" BOOK: Building Super Calculators and Minicomputer Hardware with Calculator Chips. By R. P. Haviland. 320

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INTERACTIVE COMPUTER GRAPHICS. By S. S. WALKER. 176 pp., illus. Written to provide a simple yet comprehensive introduction for potential designers and developers of hardware and software, this book first introduces general concepts in terms of basic qualities of the human and physical capabilities of the machine. 767/661 Pub. Pr., $14.50 Club Pr., $12.30

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MINIPROCESSORS: From Calculators to Computers. By DAVID HEISERMAN. 195 pp., illus. If you like to tinker with calculator circuits, this book shows you just how far you can push them. A lot of fun but with serious intentions, it is a machine -language hybrid calculator guide that you'll use for years. 784/71X Pub. Pr., $9.95 Club Pr., $8.45

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may return the books within 10 days and request that my membership be cancelled. If I keep the books, I agree to take a minimum of three additional books during the next two years at special Club prices (guaranteed 15% discount, often more). I will receive the Club Bulletin 13 times a year. If I want to examine the featured selection, I need take no action. It will be shipped automatically. If, however, I want an alternate selection-or no book at all-I simply notify the Club by returning the convenient card always enclosed. I will always have a minimum of 10 days in which to return the card and you will credit my account fully, including postage, if this is not the case. Membership in the Club is continuous but cancellable by me at any time after the four -book purchase requirement has been filled. This order subject to acceptance by McGraw-Hill. Or- ders from outside the continental U.S. must be prepaid. Company, business or institutional tax exemption status is not applicable to purchases made through individual Club memberships. All prices subject to change without notice. Offer good for new members only Postage and handling charges are added to all shipments. Members are billed when books arrive.

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APRIL 1979 63


SI

117 VAC

Fig. 10. Component placement for the power tixpply board shown a hove.

are not required in the Morse -A -Word and the pc locations for them should be ignored. When you have completed assembly of the board, apply line power to it and verify that the desired voltages are being produced. If the voltages are correct, remove line power and interconnect the supply and main pc boards with suitable lengths of color -coded hookup wire. Then mount the boards in the project enclosure and connect the free ends of the hookup wires already soldered to the main pc board to speaker, jacks, etc. A cutout for the displays must be made on the front panel of the enclosure. This can best be done with a nibbling tool. For those who prefer a prepunched enclosure, one is available from the kit supplier. Display contrast and project appearance will be enhanced by install- ing a bezel and red filter in the cutout.

Apply power to the project. Several or all of the dual -character displays should start to glow. If they don't, disconnect power and go back and thoroughly check for loose wires, cold solder joints, solder bridges, or incorrect wiring.

Alignment. The center frequency of the bandpass filter and the tone decoder's peak response frequency must be the same if the Morse -A -Word is to function properly. Any frequency between 800 and 2600 Hz is suitable, but the higher frequencies will produce a better circuit response. On the other hand, the higher frequencies tend to be more difficult to tune on a highly selective communications receiver. As a compromise, 1200 Hz was selected as the center frequency of the band-pass filter and the tone decoder.

To align the project, apply a 0.5 -volt rms, 1200 -Hz signal to the receiver input jack. Connect an ac voltmeter or oscilloscope to the output of the bandpass filter (TP1) and adjust trimmer potentiometer R9 for maximum output. Next, adjust

R20 until a tone is heard in the speaker and the CODE LED lights. Reduce the input signal to as low a level as possible and repeat the procedure. If a 1200 -Hz signal is not available and you have a cassette tape recorder, a cassette tape available from the kit supplier has the necessary tone recorded on it. The tape also includes recordings of sample Morse code messages and selections which can be used for code practice.

The only other adjustment is the setting of trimmer potentiometer R14, which determines the loudness of the speaker output. A low volume setting is

TABLE I TRUTH TABLE FOR 1702A PROM IC14

Character Input Output A7 A6 A5 A4 A3 A2 Al AO D8 D7 D6 D5 D4 D3 D2 D1

A 0 1 1 0 1 0 1 1 1 1 0 0 1 0 0 1

O 0 1 0 1 0 1 1 0 1 0 0 1 0 0 1

B 0 1 1 1 1 1 0 0 1 0 0 1 0 0 0 0 0 0 1 1 1 1 0 0 1 1 0 1 1 0 0 1

C 0 1 1 1 0 1 0 0 1 1 0 0 0 0 0 1

O 0 1 1 0 1 0 0 1 0 0 0 0 0 0 0 D 0 1 1 1 1 0 0 1 1 0 0 1 0 0 0 0

O 0 1 1 1 0 0 1 1 1 0 1 0 0 0 1

E 0 1 1 1 0 1 1 1 1 1 0 0 1 0 0 1

O 0 1 1 0 1 1 1 1 0 0 0 0 0 0 0 F 0 1 1 1 0 1 1 0 1 1 0 0 1 0 0 1

O 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0 G 0 1 1 1 0 0 0 1 1 1 0 0 0 0 0 1

O 0 1 1 0 0 0 1 1 0 0 0 1 0 0 1

H 0 1 1 1 1 1 1 0 0 1 0 0 1 0 0 1

O 0 1 1 1 1 1 0 0 1 0 0 1 0 0 1

0 1 1 1 1 0 1 1 1 0 0 1 0 0 0 0 0 0 1 1 1 0 1 1 1 0 0 1 0 0 0 0

J 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 1

O 0 1 0 0 0 1 0 1 1 0 0 0 0 0 1

K 0 1 1 0 1 0 0 1 0 1 0 0 1 0 0 1

O 0 1 0 1 0 0 1 0 0 1 0 0 1 0 0 L 0 1 1 1 1 0 1 0 0 1 0 0 0 0 0 1

O 0 1 1 1 0 1 0 1 0 0 0 0 0 0 0 M 0 1 1 0 0 0 1 1 0 1 1 0 0 0 0 1

O 0 1 0 0 0 1 1 0 1 1 0 0 0 0 1

N 0 1 1 1 0 0 1 1 0 1 1 0 0 0 0 1

O 0 1 1 0 0 1 1 0 1 0 0 0 1 0 1

O 0 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1

O 0 1 0 0 0 0 1 1 1 0 0 0 0 0 1

P 0 1 1 1 0 0 1 0 1 1 0 0 1 0 0 1

O 0 1 1 0 0 1 0 0 1 0 0 1 0 0 0 O 0 1 1 0 1 0 0 0 1 1 0 0 0 0 0 1

O 0 1 0 1 0 0 0 1 1 0 0 0 1 0 1

R 0 1 1 1 0 1 0 1 1 1 0 0 1 0 0 1

O 0 1 1 0 1 0 1 0 1 0 0 1 1 0 0 S 0 1 1 1 1 1 0 1 1 0 1 0 0 0 0 1

0 0 1 1 1 1 0 1 1 1 0 0 0 1 0 0 T 0 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0

O 0 1 0 0 1 1 1 0 0 0 1 0 0 0 0 U 0 1 1 0 1 1 0 1 0 1 0 0 0 0 0 1

O 0 1 0 1 1 0 1 1 1 0 0 0 0 0 1



recommended to avoid confusion when

listening to both the receiver and the

Morse -A -Word simultaneously.

Use. The Morse -A -Word is easy to op-

erate. The setting of the front -panel

SPEED control (R28) is the only adjustment that must be made, and only a

rough setting is required. Keep in mind

that the Morse -A -Word has a sensitive input stage, so don't set the receiver au-

dio gain control higher than is neces-

sary. When the receiver is tuned to the

center of the filter passband (1200 Hz),

you should hear audio from the project's

internal speaker and the code LED

should flicker in time with the incoming

code. The passband is only about 120

Hz wide, so some care is required when

tuning in a signal. With the signal properly tuned in, ad-

just the SPEED control SO the DAH LED

glows only when dahs are sent, and not

dits. The alphanumeric readout LED will

now display the incoming characters. If

word spaces are desired, make sure the

WORD SPACE switch is closed. Only a

few amateur stations actually send word

spaces, so don't expect perfectly spaced copy unless you are tuned to a

V 0 1 1 0 1 1 1 0 0 1 0 0

O 0 1 0 1 1 1 0 0 0 1 0

W 0 1 1 0 0 1 0 1 0 1 0 0

0 0 1 0 0 1 0 1 0 1 0 0

X 0 1 1 0 1 1 0 0 0 0 1 0

O 0 1 0 1 1 0 0 0 0 1 0

Y 0 1 1 0 0 1 0 0 0 0 1 0

O 0 1 0 0 1 0 0 0 0 1 1

Z 0 1 1 1 1 0 0 0 1 0 0 0

O 0 1 1 1 0 0 0 1 0 1 0

0 0 1 0 0 0 0 0 0 1 1 0 0

O 0 0 0 0 0 0 0 1 1 1 0

1 0 1 0 0 0 0 0 1 0 0 0 1

O 0 0 0 0 0 0 1 0 0 0 1

2 0 1 0 0 0 0 1 1 1 0 0 0

O 0 0 0 0 0 1 1 1 1 0 0

3 0 1 0 0 0 1 1 1 1 0 0 0

O 0 0 0 0 1 1 1 1 1 0 0

4 0 1 0 0 1 1 1 1 0 1 0 0

O 0 0 0 1 1 1 1 0 1 0 0

5 0 1 0 1 1 1 1 1 1 1 0 0 O 0 0 1 1 1 1 1 1 0 0 0

6 0 1 0 1 1 1 1 0 1 1 0 0

O 0 0 1 1 1 1 0 1 0 0 0

7 0 1 0 1 1 1 0 0 1 0 0 0

O 0 0 1 1 1 0 0 0 1 0 0

8 0 1 0 1 1 0 0 0 1 1 0 0

O 0 0 1 1 0 0 0 1 1 0 0

9 0 1 0 1 0 0 0 0 1 1 0 0

O 0 0 1 0 0 0 0 0 1 0 0

O 1 0 0 1 0 1 0 0 0 0 0

O 0 0 0 1 0 1 0 0 0 0 0

O 1 0 0 0 1 1 0 0 0 0 0

O 0 0 0 0 1 1 0 0 0 0 0

0 1 0 1 1 0 0 1 1 0 0 0

0 0 0 1 1 0 0 1 0 1 0 1

/ 0 1 0 1 0 1 1 0 0 0 0 0

O 0 0 1 0 1 1 0 0 0 1 0

- 0 1 0 0 1 1 1 0 0 0 0 0

O 0 0 0 1 1 1 0 0 0 0 0

Space 0 1 1 0 1 1 1 1 0 0 0 0

0 0 1 0 1 1 1 1 0 0 0 0

AR 0 1 0 1 0 1 0 1 1 1 0 1

0 0 0 1 0 1 0 1 0 1 0 1

SK 0 1 0 0 1 0 1 1 1 1 0 1

0 0 0 0 1 0 1 1 1 0 1 1

KN 0 1 0 1 0 0 1 0 0 1 0 0

0 0 0 1 0 0 1 0 0 0 1 1

AS 0 1 0 1 1 1 0 1 1 0 1 1

O 0 0 1 1 1 0 1 1 0 1 1

'Y151tlij

i -c _

Ifs !

BHURE

. -- u

ttheN fac . does more... much more!

Era IV begins! The new Shure V15 Type IV phonograph cartridge is an altogether new phono cartridge system that exceeds previous performance levels by a significant degree - not merely in one parameter but in totality. The Type IV offers:

Demonstrably improved tracka- bility across the entire audible spectrum. Dynamically stabilized tracking overcomes record -warp caused problems, such as fluctuating tracking force, varying tracking angle, and wow. Electrostatic neutralization of the record surface minimizes clicks and pops due to static discharge, electrostatic attraction of the cartridge to the record, and attraction of dust to the record. An effective dust and lint re- moval system. A Hyperelliptical stylus tip configuration dramatically reduces both harmonic and intermodulation distortion. Ultra -flat response - individually tested.

V15

SUPEReIv TaCKIV R Stereo Dynetics Phono Cartridge

For complete details on this remarkable new cartridge write for the V15 Type IV

Product Brochure (ask for AL569) and read the exciting facts on the V15 IV for yourself.

P SHURE Shure Brothers Inc.

222 Hartrey Ave., Evanston, IL 60204 In Canada:

A. C. Simmonds & Sons Limited Manufacturers of high fidelity components, microphones, sound systems, / and related circuitry. //

APRIL 1979 CIRCLE NO.55 ON FREE INFORMATION CARD


1, 10, rte" s'1:#'-

E

É

E

J..

1]

ti

A

Get the inside story... on software, hardware, simulations, computer games, robotics, computers and calculators, languages and compilers, custom systems design and scores

Read BYTE. of applications.

BYTE, the leading magazine in the personal computer field, will keep you aware of fast -paced changes in the ever growing world of microprocessors. You'll find BYTE tutorials invaluable, reports on home computer applications instructive, and the reviews of computer products stimulating. Tutorial information in BYTE is of interest to both the beginner and experienced computer user. BYTE's editorial content explores the fun of using and applying computers for personal satisfaction in activities from electronic music to electronic mail,

Fill in and mail the coupon today. Read your first copy of BYTE. If it is everything you expected, honor our invoice. If it isn't, just write -Cancer on the invoice and mail it back You wont be billed and the first issue is yours at no charge.

from games to pragmatic personal business. In BYTE is found authori- tative yet easily read coverage of principles of computer hardware and software design, approaches to novel applications, and essentials of proven interest to personal computer enthusiasts.

Each month serious computer users read BYTE. They're rewarded with timely articles by professionals, computer scientists and competent amateurs. Isn't it time you got the inside story? Subscribe now to BYTE, the Small Systems Journal.

Allow 6 to 8 weeks for processing. If you have any ouestiors, dial toll free 800-258-5485. This is the number of the BYTE Subscription Department.

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61111 1"1111111.41~1"111111111 AILMIMO 1111~~11 ~O -1.~.~N, MRS 1Mere-~ =WO !JIM 11111-~1111111 CIRCLE NO.8 ON FREE INFORMATION CARD 66

Name (please print)

Code

7349

TABLE II SOME COMMERCIAL

CW STATIONS Frequency

Station (MHz) NSS 8.090 WSL 8.516 WAX . 8.527 WCC 8.587 WCC 8.590 NBA 8.617 NAM 12.134 NMN 12.720

NAWS 12.725 WCC 12.926 WSL 13.026

NAWS 15.921 WCC 16.935

Traffic Weather Bulletins Commercial Press

Messages Messages Messages Telegrams

Weather Bulletins High Speed CW

Weather Bulletins Messages Messages Messages Messages

station such as W1AW which sends machine -perfect code. Invalid Morse characters will be displayed as blanks.

For code practice sessions, connect your telegraph key to the KEY jack and adjust the SPEED control for the approximate sending speed. You can calibrate your SPEED control using the formula: Speed (WPM) = 0.15f. That is, the code speed in words per minute equals fifteen hundredths of the clock frequency as set by the SPEED control.

An excellent source of code material is amateur station W1AW, operated by the American Radio Relay League. The station transmits several code practice sessions each day, as well as ham news bulletins, propagation forecasts and OS- CAR bulletins, all in Morse code, on 3.58, 7.08, 14.08, 21.08 and 28.08 MHz, as well as vhf frequencies. For a complete W1AW operating schedule, send an SASE to ARRL, 225 Main St., New- ington, CT 06111.

Commercial CW stations that transmit ship -maritime, press, and weather messages are also valuable sources of code practice. Table II is a list of eight shortwave stations that you'll want to tune in if you have a general -coverage receiver. Whether you plan to confine your listening to the ham bands or branch out into the other shortwave frequencies, remember that a good antenna and a sensitive, stable communications receiver play key roles in good CW reception.

One final note-international radio regulations prohibit the disclosure to others of any information gleaned from press or commercial transmissions. Ac- cordingly, it is illegal to pass information so obtained (except that learned from amateur radio or broadcast transmissions) to a third party.

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Microcomputer I/O Board Buying Directory

Make & Model Price'

(5)

+8V

Power required

(mA)2'

+16V -16V

RAM capacity

min. max.

Expansion

kit size

and

price

Speed

Ins)

Type_

-

Min.

addr.

block size BS

Features2

BB WS WP

S-100

Advanced Computer Prods.

LOGOS 1 126 (k) 8K 8K none 450 X X

150 (w)

LOGOS 1Z 150 (k) 8K. 8K none 250 X X

200 (w)

Base 2

8KS.B 125 (k) X 8K 8K none 500 stat. 4K X X X

150 (w)

8KS.Z 145 1k) X 8K 8K none 250 stat. 4K X X X

170 (k) 16S -B 285(k) X 16K 16K none 500 stet. 4K X X X

310 (w) 16KS-Z 325 )k) X 16K 16K ' none 250 stet. 4K X X X

350 1w)

Central Data

16K RAM 289 (w) 300 150 20 16K 32K 16K/$200 450 dyn. 16K

32K RAM 475 1w) 00 150 20 32K 32K none 450 dyn. 16K

CGRS Microtech

16K RAM 450 1k) 16K 16K none stat.

490 (w)

Chrislin

CI -S100 390 16K 64K none 300 dyn.

650 32K 300 dyn.

825 48K 300 dyn.

995 64K 64K none 300 dyn.

Computerware, Inc.

8K Static 146 1w) 8K 8K none 450 stat. X

186 (w) 8K 8K none 250 stat.

350 (w)

Cromemco

4KZ 195(k) 800 4K 4K none 450 stat. X X

295 (w) 16KZ 495 )k) B00 599 19 16K 16K none 200 stet. X

795 (w)

Digital Micro

Systems

OM 16K (w.8K) 35 (b) 2A 8K 16K 8K 350 stat. 4K X X

275 1k)

DM16K 35')B( 2A 16K 16K none 350 stat. 4K , X X

465 (k) 495 (w)

Dynabyte MD161 399 (w) 8A .5A 16K 16K none 459 dyn. 8K

MS1645 525 (w) 1.6A 16K 16K none 300 star. 4K X

MS1625 555(w) 1.8A 16K 16K none 250 stat. 4K X

MS3245 925 (w) 3.1A 32K 32K none 300 stet. 4K X

MS3225 995 1w) 3.8A 32K 32K none 250 stat. 4K X

Electricom 4020 287 (w) 2K 2Kx9 $10 250 X

Remarks

Hardware protect in

256 -byte to 8K incre-

ments, switchable from top of board.

250nsversion.

250-nsversion.

Phantom disable.

Phantom disable.

Wait states only @ 4 MHz on non -se -

quential'address.

Alph-Micro DMA

compatible; also

arailableas kit less RAM,

$95.

Transparent refresh

DMA compatible.

On -board battery, charg-

er and power -state

monitor; wire -wrap ribbon -cable or S-100

connection.



can you be

bribed? You get a $35.21 bribe when you try only 10 DAK ML90 high energy cassettes for only $2.19 each!

Hats off to Maxell. Their UDXL cassette established a new standard of quality for all cassettes.

The new DAK ML90 starts another new technology. A technology of ex- treme reliability and protection from Hi frequency losses.

Later we are going to offer you a valuable bribe, if you will test these cassettes, risk free; so read on!

YOUR TIME IS PRECIOUS Imagine yourself just finishing record-

ing the second side of a 90 minute cassette and horrors, the cassette jams. Tape is wound around the capstan, your recorder may be damaged and you've just wasted 90 minutes of your time and perhaps lost a great recording off FM.

I'm sure this is one experience we all dread, and is one of the main reasons to buy name branded guaranteed tape you can trust.

Enter DAK. We manufacture over one million units of cassette tape each month, and many of our cassettes are used for high speed duplication, which causes more cassettes to fail than any other use.

When we first started, DAK's cassettes failed, just like many others. So we installed over $20,000 worth of high speed duplication equipment at our factory and set out to design the perfect cassette.

FAILURE Failure after failure. We substituted,

remade, tested and retested the over 20 parts of our cassette, and checked everyone elses cassettes. Finally after over 6 years we positively linked cassette failure or the prevention of failure to the slip sheets, or liners in the cassette.

We were not alone. Scotch, TDK, and several others must have been doing the same research because they have also been coming out with special improved slip sheets.

MOLYSULFIDE A new chemical named molysulfide,

that reduces friction within the cassette several times better than graphite gave us success.

We developed polyester slip sheets with raised spring loaded ridges coated with a unique formulation of molysulfide and graphite.

The tape ran more smoothly than ever before within the cassette. The new formulation is also much tougher than the graphite formulation, so it is extremely resistant to wear.

Static electricity within the cassette was drastically reduced by the low friction, and easily bled off, so its tendency to erase very high frequencies was drastically reduced. A very important consideration for often played tapes.

The molysulfide formulation gives both superior electrical and mechanical performance, thus it has formed the

)

10 free 6 ft RCA to RCA hook up cords -2 1~.00.. 6ki,bHúr:as1 -°'.1.1:lg'}r.1430" ~VAW:yL°'.k,'...., o bnl.p no, mal

: DAK

Incorporated n pIncorporatedIncorporated

. - (4°E eAp'k1 9iHIGH

r Lp 0

*'

, .,...-'.,

o.

S.

, . b . !!m:' .;>;:>, ';`.,:

basis for the birth of the new DAK ML cassette.

MAXELL IS BETTER Yes honestly, if you own a $1000 cas-

sette deck like a Nakamici, the frequency response of Maxell UDXL is superior to DAK and you just might be able to hear the difference.

DAK ML has a frequency response that is flat from 40cps to 14,500cps Virtually all cassette recorders priced under $600 are flat from 40cps to about 12,000cps, so we have over 2000cps to spare, and you'll probably never know the difference.

No apology We feel that we have equalled or exceeded the mechanical reliability of virtually all cassettes and offer one of the best frequency responses in the industry. Maxell UDXL is truly the Rolls Royce of the industry, and DAK is the 100% US made Cadillac or Corvette!

Price DAK manufactures the tape we sell, you avoid paying distributor and retailer mark ups. While Maxell UDXL 90s may sell for $3.50 to $4.50 each, DAK ML9Os sell factory direct to you for only $2.19 each.

YOU WIN You are paying less for the 10 90

minute cassettes than you would pay for the bribes we are offering if you went to a Radio Shack Store.

DAK AC ADAPTOR

M IR III -1{]{N MIL. I 10 ]M WM 10 {IV

UL

Yours Free

CHECK THE VALUE OF THE BRIBES AT RADIO SHACK

Think of it, 10 six foot hook up cords with RCA plugs at each end. Whether you use the cords now, or when you buy new equipment, those of us who are tape recorder nuts, never seem to have enough. Radio Shack sells six foot cords for $1.89 each.

.You will find dozens of uses for this deluxe battery eliminator AC adaptor around your home or office. 4 voltages, 3, 4.5, 6 and 9 volts. 4 plugs will fit virtually any calculator, radio, or battery operated recorder we have seen. You'll save a lot of money on batteries. Radio

Shack sells a similar 4 voltage adaptor for $9.95.

The deluxe 12oz can of spray head cleaner will clean your tape heads for years to come. The handy snorkel included, can reach just about any tape head, even 8trk heads. Radio Shack does not sell a large 12oz can, but 12oz from them costs $6.36.

The Radio Shack prices are not list prices, but the actual prices you would pay when you walk in the door.

DAK

TAPE HEAD

CLEANER

Yours Free

WE WIN TOO Customers like you are very valuable

in the form of future business. We an- ticipate receiving over 6000 orders and 4500 repeat customers from this advertisement. We are betting you will buy our cassettes again, and we are putting our money where our mouth is!

TRY DAK ML90 FREE We want you to try these high energy

cassettes on your own recorder without obligation for 30 days. If you aren't 100%. satisfied for any reason, simply return the tapes and bribes to DAK for a full refund.

To order your 10 DAK ML90 minute high energy cassettes and receive your $35.21 bribe with your credit card, simply call toll free 800, 423-2636, (in Calif. call 213-984-1559) or send your check for $21.90 plus $3 for postage and handling for each group of 10 cassettes and bribes to DAK. (Calif. residents add 6% sales tax).

DAK unconditionally guarantees all DAK cassettes for one year against any defects in material or workmanship.

Why not order an extra group of 10 DAK ML90 cassettes for yourself or a friend? We will add one free ML90 cassette fc reach additional 10 you buy and of course you get all 3 bribes with each group of 10 tapes.

DA K gici INDUSTRIES

INCORPORATED

Call TOLL -FREE (800) 423-2636 In California Call (213) 984-1559 10845 Vanowen St., North Hollywood, CA 91605

APRIL 1979 CIRCLE NO. SOON FREE INFORMATION CARD fig


I/O BOARD BUYING DIRECTORY continued

Make & Model Price'

(S)

Power required

(mA12

RAM capacity, i Expansion' -

kit size

and

Speed

(ns)

¡; Type, ¡ Min.

addr.

'block

Features2 -

+8V +16V -16V min. max. ; price size -BS B8 WS WP

Electronic Control Technology 16K RAM 350 (k) 1.5A 16K 16K none 450 slat. '16K X

399 1w)

16K RAM 4MHz 415 (k) 16K 16K none 250 stat. 16K X 475 (w)

Electronic Systems

300 23(b) 1K 250 star. X 160(k) 200 (w)

Fire Bird Sales

16KRB 323 (w) 16K 16K none 260 ' dyn. 16K X

Franklin Electric 8KSr 249 (k) 1.2A 8K 8K , none 400 stat. 2K X X X

295 (WI 8KSh 289 (k) 1.7A 8K 8K none 250 ' , stat. 2K X X X

330 1w)

Godbout

Econoram II 135 (k) 1.5A 8K 8K none stat. 4K X X 155 (WI

Econoram IV '279 (k) ' 2A 16K 16K none stat. 16K X 314 (w)

Econoram V '279 tic) 2A 16K 16K none slat. 16K X 314 (w)

Econoram VII 445 1k) 2A 24K' 24K - none ' stat. 2, 4K: X X 485 (w) 2, 8K

GRE Data Products

232-8 119 (W) 1.2 8K 400 stat.. . 8K

232.16 319 (W) 16K 400 slat. ;.16K X

IMSAI RAM 4A-4 139 1k) l 800 4K, 4K none 500 stat. 4K X

189 (w) RAM 16 449 (k) 500 150 10 16K 1.6K none 500 dyn. 4K` X

499(w) RAM III -32 895 (w) 360 250 10 32K 32K none 500 dyn. 4K" X RAM III.64 1695(w) 360 250 10 64K 64K none 500 dyn. 4K' X

Industrial Micro systs.

C00232 , 135 8K BK low . stat. C002324HS 150 8K 8K hi stat. C00282 304 16K 16K low stat. C002824HS 343 16K 16K ' hi stat. C00360 625 32K 32K ' low stat. C00360 -HS 689 , 32K 32K hi stat.

Ithaca Audio 8KSR 25(b):- 1.4A 1K 8K stat. 4K X X X X

160 (w) 1,4A 8K 8K 450 stat. 4K X X X X 199(w) 1.4A 8K 8K 250 ' stat. 4K X X X X

16KDR 35 (b) 1.4A 16K 64K dyn.

Jade Computer JG8K 25 (b) 2.5A 8K ' 450 stat. 8K X X

126 (k)

150 1w)

140 1k) 2.5A 8K 350 stat. 8K X X

160 (w)

170 (k) 2.5A 8K 250 stat. 8K X X

190 1w)

Micro Data

Systems

MD -697(8K) 179 (k) 1.5A 8K 32K, 8K/$129. 450 stat. 1. 16K X

199 (w) M0-697 (16K) 308 (k) 1.5A 16K 32K 8K/$129 450 stat. ' 16K X

348 (w) MO -697 (24K) 437 (k) 1.5A 24K 32K ;. 8K/5129 450' stat. 16K X

497 (w)

Remarks

Spare IC spaces

for user circuit. Spare IC spaces

for user circuits.

Bare -board version

includes

regulator.

LED indicators for power OK, board

select, write -pro - tect; DI P addr. SW.

Software write protect w. vector.

Write -protect for' 4K blocks. Manual high-8K/low- 8K deselect.

Can deselect either 4K/8K pair.

Provisions for MWRT and Phantom

disable.

"4K block missing

with memory -map option. As above.

As above.

Softwáreprotect/unprotect.

Adapter ($13) avail-

able for use with Motorola D-2 6800 Eval. Kit.

250-ns option avail.

250 ns optional.

' 250-ns optional.



o

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APRIL 1979 CIRCLE NO.4 ON FREE INFORMATION CARD 71



Make & Model

,

MD -697(32K)

Price'

($)

539 1k)

599 (w)

Power -required

(mA)z '

+8V +16V

1.5A

-16V

RAM capacity

' min. max.

32K 32K

Expansion

kit size F and

price

none

Speed

(ns)

450

Type Min.

adds.

block

size

stat. 16K

BS

X

Features3

BB WS WP

National Multiplex 8K 190 1w) 8K 8K stat.

North Star

RAM -16 399 (k) , 600 400 100 16K 16K none 250 dyn. 8K 459(w)

Novel

32K RAM 650 32K 32K 2MHz dyn. 8K

Pacific Digital

8KRS (450) 150 1w) 2A 8K 8K none 450 stat. ' 4K X 8KRS (250) 190 1w) 2A 8K BK none 250 star. 4K X

Parasitic

Econoram III 188 (w) 350 155 8K BK none 250 dyn. 4K

Piiceon

SupeRam 2 1150 (w) X X X 48K 64K 16K/S220 2 -MHz dyn. 16K X

Polymorphic 81( RAM 300 Ik) 2.6' 500ns X

Processor Tech.

OKRA 125 1k) IA 4K 4K none 460 slat. 150 1w)

OKRA 225 )k) I.9A 8K . 8K none 400 slat. 250 1w)

16KRA 429 (w) 800 150 20 16K 32K none 400 dyn. 4K 32KRA 750 1w) 800 150 20 32K 32K none dyn.

Quay

080 SMB 235 1w) BK 8K none 450 star. X X

Seattle Computer

24-101 375 1w) 1.8A 16K 16K none 494 stat. 4K 425 1w) 1.8A 16K 16K none 294 stat. 4K

SCP-16K 425 (w) 1.94 16K 16K none 471 stat. 4K X

475 (w) 1.9A 16K 16K none 271 slat. 4K X

Solid State Music

MB4 91 (k) 1.1A 4K 4K none 2 MHz stat. 4K X X

MB6A 165 1k) 2,0A 8K 8K none 2 MHz star. 8K X X X

175 (k) 2.0A 8K 8K none 4 MHz stat. 8K X X X

MB 449(k) 550 80 25 16K 16K none 2-3 MHz stat. 16K X

MR -9 PROM/RAM BO (k) X 0 4K stat. X

Space Byte 16K 599(w)' 1.6A 16K 16K 450/ stat. 4K X X

250

Thinker Toys

EconoRam III 159 (k) 240 80 20 8K 8K none 471 dyn. 4K

149 (w)

Super Ram 299 (k) 2A 16K 16K none 450 stat. 4K X

334 1w)

Remarks

250-ns optional.

Parity option, $39 (k),

$59 1w).

Hardware disable for any

8K block.

"Invisible refresh".

DMA -compatible; uses

digital delay lines;

software or hardware

bank select.

`Standby power, 1.5A @ 2.2V; phantom disable.

Memory protect in 4K

blocks.

Parallel addressing

capability.

Memory protect in 4K

blocks.

Memory protect to 256-

byte blocks; phantom provisions.

4K memory protect;

phantom provision.

Can intermix RAM and

PROM in 256 -byte increments; jump on

reset or on power -up.

Phantom disable and

write protect for

each 4K; DMA -compatible.

With Synchrofresh.



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- Make & Model Price''

(5)

Power required w

(mA)Z RAM capacity Expansion

kit size

and

Speed'

(os)

Type Min. = addr.

block

Features3 Remarks

+8V . , +16V -16V min, , max. price size BS, BB WS WP

Trace Electronics 1600 499 (w) 1.7A 4K 32K 16K/$256 450 stat. X DMA -compatible; 599 (w) ' 1.7A 4K 32K' ' 16K/$356 250 stat. X phantom provision;

"Megex tend" can ad - 3200 749 (w) 13.3A 32K 32K none 450 stat. X dress to 11v1 bytese 849 (w) 3.3A 32K 32K none 250 stat. X with 4 -bit output port.

Vector Graphic 8KF 245 (w) I IBA 8K 8K none 250 stat.. 8K X X Phantom disable. 16K 485 (w) I 1.8A 16K 16K none 300 stet. X Phantom disable. ,

Wameco

MEM1 30 (b) 1K 8K 450 stat. 8K X 250 (k) 295 (w)

MEM-2 30(b) 4K 16K 450 stat. BK X X 665 (k) 695 (w)

Xitan

Z-16 . 489 (w) ' 205 105 16K stat. 4K X X Write protects each 4K. D.16 489 (w.) 16K dyn. 4K X

D-32 869 (w) 32K ' dyn. 4K X K-32 -.799Iw) 190 250 32K 32K none 4MHz dyn.'1 32K X "-5V @ 15 mA; transparent

refresh; 4K block de -

selection (switched). K.48 1099 (w)I 190 250 48K 48K none 4MHz dyn.', 48K X As above, but 8K deselect. K-64 1299 (w) 190 250 X 64K 64K none 4MHz I dyn` I' 64K X "As above. K-128 2599 I 190 250 X 128K 128K none 4MHz dyn." 128K X "As above, 16K deselect.

Notes:

Ibl=bare board: (k)=kit; (wl=wired. 'In amperes where indicated by 'A.' 38S=hank-select or memory -mapping option; BB=battery backup; WS=wait.stateS; WP=write-protect.

'See -Remarks" column.

a

Make & Model - Price'

(SI

' Power required

(mA)z

+8V , +12V -12V

RAM capacity

min. max.

Expansion kit size,

and

,price '

-Speed

Ins)-

Type Mina "

addr,

block ' BS

'Features'

BB ` WS WP

SS -50

Digital Service

& Design

DSD 2114-16K 27 (b( 9.5A 1K (6K 450 stat. 8K X

Gimix 16KWR 4951w) i 1.64 16K 16K none 450 star. , 4K X X

Midwest

Scientific RAM -68 225 (k)" X 8K 8K X

335(w)"

Smoke Signal M-164 319 (w) I 1.6A 16K 16K none 250 stat. _ 16K

Southwest Tech

Products M P -M 65 (k) t 750 2K 4K 2K/S35 r 500 stat. MP -BM 250 (k) ' IA 8K 8K none 500 stet. MP -16 400 (w) X X 16K 32K 16K/$250 500 dvn. -

Remarks

Software -controllable addressing, disable/en-

able, write -protect, register -select.

'Sockets, S35.

DMA -compatible.



Make & Model Price'

IS)

Power required

(mA)'

+51/ -5V ±12V

RAM capacity

min. max

Expansion

kit size,

and

price

Speed

Ins)

Type Min.

addr.

block

size BS

Features'

BB WS WP

Remarks

SBC MULTIBUS

Chrislin

CI -8080 390 16K 300 dyn.' '0n -board refresh.

650 32K 300 dyn.'

825 48K 300 dyn.'

995 64K 300 dyn.'

Datacube

RM-117 1200 (w) X 16K 1M use CM118350 stat. BK X X Dual -port memory. sys-

tem allows 2 SBC buses

to share common memory

w. Intel 8086.

CM -118 1250 1w) X 32K 32K 350 stat. 32K Usable as stand-alone

32K RAM w. BK PROM,

or as stave memory.

Electronic

Solutions RAM -4 295 1w) 1.2A 4K 4K none 400 star. 4K

RAM -4L 312 1w) 1.2A 4K 4K none 400 star 4K X With battery back-up.

RAM -8 395 1w) 2A 8K 8K none 400 slat. 8K

RAM -8L 428 (w) 2A 8K 8K none 400 stat. BK X With battery back-up.

National

Semiconductor

BLC-016 784 (w) 1.5A 10 700 I6K 16K none 435 dyn. 16K X No wait states with

BLC-032 1292 1w) 3.0A 47 11 32K 32K none 430 dyn. 16K X X X BLC 80/204 CPU.

BLC-048 1767 1w) 3.0A 47 11 48K 481 none 430 dyn. 16K X . X X

BLC-064 2090 1w) 3.0A 47 11 64K 641 none 430 dyn. 16K X X X

Xycon Xycon 16 684 (w) 16K 32k. 250 star. 8K X X

Xycon 32 1024 (w) 32K 32K 250 star. 8K X X

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Experimenter's Corner

THE ANALOG SAMPLE/HOLD CIRCUIT

MICROPROCESSOR enthusiasts are constantly seeking simple

ways to interface small controllers and computers with the outside world of analog signals. One well-known analog circuit with many interfacing applications

By Forrest M. Mims

mains almost constant for an appreciable amount of time.

The op amp is connected as a voltage follower with unity gain. This arrangement permits the charge on the capacitor to be measured by a standard mul-

Fig. 1. Schematic of a demonstration sample/hold circuit.

is the op -amp sample/hold (or sample and hold) circuit.

A sample/hold circuit stores in a capacitor the instantaneous voltage present at its input. The stored voltage, which can represent anything from the intensity of light illuminating a photocell to an audio signal, can be converted into digital form by an analog -to -digital converter for processing by a microprocessor. What's more, a sample/hold stage can be used in many different analog applications.

Simple Sample/Hold Circuit. Fig- ure 1 schematically shows a very simple but functioning sample/hold circuit. The key component of the circuit is capacita - tor C1. When switch S1 is momentarily toggled to its SAMPLE position, the capacitor charges to the voltage present at the input. The charge on the capacitor is monitored by ICI, an op amp with a very high input impedance, which should be an NE536 or similar amplifier with a FET input stage. When switch S1 is released, it returns to its center (off) HOLD position and disconnects Cl from the input of the circuit. Because the op amp's input impedance is very high, the charge stored in the capacitor is effectively trapped and the voltage across Cl re-

timeter without significantly altering the amount of stored charge. Connecting a conventional, low -input -impedance voltmeter across the capacitor would, of course, quickly drain the capacitor of its charge. After the magnitude of the voltage sample has been determined, the switch can be momentarily placed in its RESET position to remove the charge from the capacitor and prepare the circuit for a new sample.

VDD +6V

V$c -6Y

It's easy to operate the circuit in Fig- ure 1. Use a 1.5 -volt cell to supply the input voltage. With the sample switch closed, adjust calibration potentiometer R1 until the meter reads 0.15 mA, which corresponds to a voltage of 1.5 volts.

You can omit the milliammeter and potentiometer if you prefer to connect a voltmeter directly to the output of the op amp. Because the op amp is connected as a unity -gain voltage follower, the voltage at its output will be identical to that at its input. This does not mean that the op amp is superfluous. To the contrary, it provides the very high input impedance that permits the voltage stored across C1 to be monitored without significant loss.

After you have sampled the input voltage, allow the. switch to return to its HOLD position and monitor the meter reading. If Cl is a high -quality, low -loss polystrene or Mylar unit, the sampled voltage will remain constant for a substantial period of time. Lower -quality capacitors including some ceramic discs will lose their stored charge at a much faster rate, as will be evidenced by a no- ticeable downward movement of the meter needle.

To increase the circuit's useful storage time, a capacitor larger than the one specified in Figure 1 can be used. But it will require a longer sample interval to charge up to the full input voltage, especially if the sample generator has a significant internal impedance.

Incidentally, if you don't have an NE536 or similar FET-input op amp on hand, you can use a standard 741 for demonstration purposes. You'll have to increase the capacitance of C1 to 1µF or more, because the stored voltage will

Fig. 2. Digitally controlled sa rnple/hold circuit using CMOS chips. To sample: make sample enable high. To reset: make reset enable high.



be lost much more rapidly than if a FET- input op amp is used, due to the 741's much lower input impedance.

Adding Digital Control. The circuit we have just described is fine for dem-

onstration purposes, but the circuit shown in Fig. 2 is more practical be-

cause the sample/hold process is controlled by logic levels instead of me-

chanical switches. As you can see by

comparing the two circuits, the ganged

sample/hold/reset switches have been

replaced by two of the analog switches in a CD4066 quad analog switch. Fur-

thermore, the NE536 has been replaced by a CA3130 MOSFET-input op amp,

but the circuit will work with the 536 as a

pin -for -pin replacement without C2.

The analog switch is a newcomer to

this column. Like the three -state gate

described in the March 1978 issue, the analog switch has an ENABLE input and ports that allow a signal to enter and leave. The analog switch, however, can transmit or block both digital logic levels and analog (variable) voltages. Like a

conventional mechanical switch, an

analog switch can pass a signal in either direction. Figure 3 shows the equivalent circuit of the analog switch.

The CA3130 op amp is also a new-

/4/./our-4.-

ENA6LE q

( (v[Ry ?War')

voltage present at the input if tie SAM-

PLE ENABLE input is still high. 01 course,

if the SAMPLE ENABLE input is low, Cl will not receive the new sample until the

SAMPLE ENABLE input is high. (Ordinari- ly, both ENABLE lines should not be

allowed to go high simultaneously. Oth-

erwise, the signal source output will be

connected to ground via a low -imped-

ance path.) As you can see, there are several op-

erating possibilities for the circuit, each of which can be readily selected by a

two-bit logic signal. The factors govern- ing the calibration of the output meter

and the selection of Cl are identical to

those that apply to the previous circuit.

Applications. The most straightfor- ward application for the sample!hold cir-

cuit of Fig. 2 is an analog memory circuit capable of storing a transducec temperature, light intensity, or pressure, or any

other analog signal for later processing. The circuit can also be used as a tim-

er. Replace meter M1 and R1 with a

LED and 330 -ohm series resistor. The LED will glow until the voltage across Cl drops below the LED's turn -on threshold. Increase the capacitance of Cl for

longer time delays. Increasing the mag-

nitude of the sampled voltage up to a

TOFF //RESISTANCE

oA///Rf3/S rANCE row)

OUT//N

Fig. 3. Equivalent circuit of a basic analog switch.

comer to this column. I'll have more to

say about both it and the CD4066 in fu-

ture columns. Meanwhile, suffice it to

say that the CD4066 is one of a family of

CMOS analog switches having many fascinating applications. The switches in

the CD4066 are off when their ENABLE

inputs are low and on when their ENABLE

inputs are high. The "off" resistance is

around 1011 ohms, and the "on" re-

sistance is typically 80 ohms. To sample a voltage with the circuit

shown in Fig. 2, the SAMPLE ENABLE in-

put, which is normally kept low, is

allowed to go high. The sampled signal level is then stored by Cl until the RESET

ENABLE input, which also is normally kept low, goes high. This allows C1 to

discharge to ground through ICIB. If the RESET ENABLE input is again

made low, Cl will immediately store the

APRIL 1979

maximum of VDD will also give longer delays.

You can create unusual sound effects by connecting the output of the circuit to

a voltage -controlled oscillator such as

the 566 function generator or unijunction transistor relaxation oscillator. For a sir-

en effect, connect a high resistance (e.g.

1 megohm) between pin 4 of ICIB and

Cl. When the RESET ENABLE input is ac-

tivated, the output voltage will slowly de- crease, causing the vco to generate a

siren -like sound. The upward wail of the

siren is obtained by connecting a sec-

ond high -value resistor between pin 1 of

IC1Aand the INPUT VOLTAGE source. No doubt you will find other applica-

tions for both circuits with which we've

been experimenting this month. I plan to

cover some of those that I have found in

a future column.

"A Technological .

Masterpiece, .: "

ar-,_ , 1

-Q-'"O'u 00000 , .,.,, ., o..... ......o.....

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international awards, and a North

American FM directory. You will

understand why McIntosh product

research and development always

has the appearance and tech-

nological look to the future.

Keep up to date.

Send now - - -

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Box 96 East Side Station

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If you are in a hurry for your catalog please

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í

Train with NTS for the MicroComputers, digital

the first name

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The world of electronics is daily becoming more challenging. Technology is growing more. specialized, and the importance of digital systems increases every day. Test instruments, home entertainment units and industrial control systems are all going digital. And now, NTS training programs include a wider choice of solid-state and digital equipment than ever before offered in any home study course: Advanced NTS/Heath digital color TV (25" diagonal with optional programming capability), NTS/Heath microcomputer, digital test equipment, digital stereo receiver (70 watts per channel), NTS compu-trainer, plus much more state-of-the-art equipment to make your training exciting and relevant.

The equipment you receive with NTS training programs is selected to provide you with a solid

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background in electronic systems. Kits and lessons are designed to work together to demorstrate electronic principles and applications. The kit -building not only shows you how electronic hardware functions, but how various circuit designs accomplish different purposes. Your lessons guide you through any number of experiments associated with many projects. This is the Project -Method, and it works. Step-by-step, you learn how and why digital electronics has become a part of our world, and the even bigger role it is sure to play in the future.

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Resident and Home -Study Schools 4000 South Figueroa St., Los Angeles, Calif. 90037

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Check if interested in G.I. all information. L Check if interested ONLY in classroom training in Los Angeles. --------J

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APRIL 1979 81


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of popular screws and nuts Ten assortments of professional qual- íty, midget, color -coded screwdrivers and/or nutdrivers . , . for popular inch and metric sizes of slotted, Phillips, Allen, Scrulox, hex head screws, and hex nuts. All capable of "double duty" with piggyback, torque amplifier handle that slips over the top of each tool for longer reach, larger gripping surface, and greater driving power. Neatly housed in compact, plastic, stand-up cases with optically clear covers for quick size -identification, making them ideal for pocket, work bench, or service kit.

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WELLER.. WISS"- XCELITE` P.O. BOX 728. APEX. NORTH CAROLINA 27502.919/762-7517

CIRCLE NO. 13 ON FREE INFORMATION CARO

English Broadcasts Audible in No. America

" = TIME' TIME '

EST/CDT UTC/GMT

4:00-4:15 a.m.

4:00-4:15 a.m.

4:00-5:00 a.m.

4:00.6:00 a.m.

5:005:05 a.m.

5:00-5:30 a.m.

5:00.5:30 a.m.

5:00 -su nrise

5:00-6:00 a.m.

5:30.6:30 a.m.

5:55-6:55 a.m.

6:00.6:15 a.m.

6:00-6:56 a.rtn

6:00-7:35 a.m:

6:00-7:50 a.m.

6:00-8:00 a.m.

- 6:00-8:30 a.m.

6:00.9:00 a.m.

6:009:00 a.m.

6:00-9:00 a.m.

6:00-10:00 a.m.

6:30.6:45 a.m: 6:30-9:00 a.m.

09000915 0900-0915

0800-1000

0900-1100 1000-1005

1000-1030

1000-1030 1000-

1000.1100

1030-1130

, 1055-1155

1-1100-1115

1100-1156

1100-1235

1100-1250

1100-1300

1100-1330

' 1100-1400

1 1100-1400

1100-1400

1100-1500

1130-1145

1130-1400

1:00.7:15 a.m. 1200-1215 7:00-7:15a.m. 1200-1215 7:00.7:30 a.m. 1200-1230

7:00-7:30 a.m. . 1200-1230 7:00.7:45 3:m. 1200-1245

7:00-7:45 a.m. 1200-1245 7:00-7:55 a'.m. 1200-1255 7:00-11:00 a.m. 1200-1600

7:15-7:30 a.m. ' i 1215-1230 7:20.7:50 a.m. 1220-1250

7:30-7:55 a.m: 1230-1255 7:30-8:00 a.m. 1230-1300 7:30-8:00à.m. - 1230-1300

7;30-8:20 a.m. - 1230-1320

(Sat)

7:30-9:20 a.m. 1230-1420

iSun) 8:00-8:15 a.m. 1300-1315

8:00-8:30 a,m. . 1300-1330

8:0010:50 a.m. 1300-1550

8:00.11:00 a.m. ' 1300.1600

8:15-'8:45 a.m. 1315-1345

8:30.9:30 a.m.

8:30-10:00 a.m.

8:30.11:00 a.m.

9:00-9:30 a.m.

9:00.9:30 a.m.

9:00-9:30 a.m.

9:00-9:30 a.m.

9:00-9:30 a.m.

9:00-9:30 a.m.

9:00-9:45 a.m.

9:00-10:00 a.m.

1330-1430

1330 1500

1330.1600

> 1400-1430

1400-1430

1400-1430

1400.1430

1400-1430

1400-1430 I

1400-1445

1400-1500

9:00.10:00 a.m. 1400-1500

9:00-11:00 a.m. 140Ól 600

9:00 a.m.-7:00 p.m. 1400.2400

9:30.10:00 a.m. 1430-1500

9:30.11:00 a.m. 1430-1600

9:30 a:m: 5:00 p.m. É

1430-2200

10:00.10:15 a.m. 1500-1515 R. Japan

10:00-11-100 a.m. 11500-1600 V. of Rev. Ethiopia 10:00-11:00 a.m. 1 1500.1600 BBC

10:00.12:00 a.m. 1500-1700 R. Moscow

10:15.10:30 a.m. 1515-1530 V. of Greece

by Glenn Hauser

BBC

R. Japan°

R. Australia

R.Oman UN Radio

R. Japan

V. of Vietnam R. Australia AFRTS

Sri Lanka Br. Corp.

R. Thailand

R. Japan,

R. OSA -

TWR-Bonaire

R. Pyongyang

R. Australia BBC

4VEH, Haiti AFRTS

VOA R. Moscow,

R.R.I. Yogyakarta

CBC Northern Service

Vatican R.

R. Japan

Israel Radio

R. Tashkent

V. of Germany R. Berlin International R. Peking

HCJB, Ecuador

V. of Greece

R. Ulan Bator, Mongolia

Austrian R.

R. Bangladesh

R. Sweden

TWR-Bonaire'

STATION : QUAD FREQUENCIES, kHz3

11955, 9640, 9510, 7150, 6195 9505 9670, 9540 11890

9565, 5955 (Sat.)

9505 12035, 10040, 9840 5995 '

6030 '

17850, 15120, 11835 (ñot all Eng. 11905, 9655

9505

21535, 25790

11815 (Sat, Sun -1220) '

11535.9977

9580 11775,6195,5990 11835,9770 15430, 15330, 11805, 9700 11715, 9730, 9565, 6185, 5955 15150, 11770

5046 9625, 6065 (nos all Eng.)

(from May, 1030.)

B 21485 8 1 9505

C 26095,21495,17685,15540;, 15415, 11655

C 9600, 9540, 6025, 5975, B 21'600, 17765, 15410

C 21540, 15320, 15125 C 9820, 6995 A 15115, 11745 B 17830,15345,11730

O 12070, 6383 (not Sun) C 21530 (frequent changes)

0 21670, 15375 (both vary) -

C 21.700

A 15255

R. Japan

R. Finland '

R. RSA

HCJB, Ecuadór

Swiss R, International

R. Finland

All India R.

BBC

10:30-11:00 a.m.,

10:30-11:15 a.m.

10:30-11:30 a.m.

10145-11:00 a.m.

R. Japan

R. Sweden

R. Norway

V. Rev. Party, N. Korea

R. Afghanistan

R. Tashkent

R. Berlin International VOA V. of Indonesia'

AFRTS CBC Northern Service

R. Finland

Burma Br. Sera

UN Radio

1530.1600 I Swiss R. International 1530-1615 NSB,Tokyo 1530-1630 V. of Vietnam 1545-1600 R. Canada International

A

B

C

0

A

B

C

B

A

C

C

B

C

A

C

A

A -B

B

A

A

B

C. B

B 9505 C 15400

B 25790, 21535, 17780, 15220

B 17890

C 21570, 21545-SSB, 21520, 15350, 17790

C 15400 (Sun. only) C 15335, 11810

B -C 21710, 17705, 15400.(1ram 1430),

15070

B 9505 B 21615 B 17840, 21730 (Sun only) D ¿ 4557,4120 O , 4775

C 9600, 9540, 6025, 5975 B 21540. 15125 A 11715,9565 C 11789

A 15425,15330,11805,9700 B -C j 11720, 9625 (nos all Eng.)

B 15400

D : 5985 A 21670, 15410 (also Frenth; when

in session)

C 9505 -.

D 9615 (frequent changes) -

B 17830, 11775 (Sat, Sun): B _: 11770,9795 B 17830, 15345, 11730

(last two, not Tues.) B - 21570 - é

C 9595, 6055

C 12035, 10040, 9840 A 17820, 15325 (Mon -Fri only)

POPULAR ELECTRONICS


11:00-1115 a.m. 1600-1615

11:00-11:15 a.m. ! 1600-1615

11:00-11:30 a.m. 1600-1630

11:00-11:30 a.m. 1600-1630

11:00..12:00 a.m. 1600-1700

11:00 a.m.-12:09 p.m. 1600-1709

11:00 a.m 1:00 p.m. 1600-1800

-11:30 a.m. -1630

11:45-12:00 a.m. 1645-1700

12:00.12:15 p.m. 1 1700.1715

12:00-12;15 p.m. 1700-1715

12:00.1:00 p.m. 1700-1800

12:00-1:00 p.m. 1700-1800

12:00-2:00 p.m.

12:05-12:55 p.m.

R. Japan

R. Pakistan

R. Korea

R. Norway

VOA

BBC

AFRTS-Washington

R. Singapore

R. Canada International

R. Japan -

Vatican R.'

HCJB, Ecuador

VOA

1700-1900 r R. Moscow

1705.1755 ; R. France International

12:10-12:55 p.m.. 1

1710-1755

12:45-3:00 p.m. 1 1745-2000

12:45-5:30 p.m.

1:00-1:15 p.m.

1:00-1:30 p.m.

1:00-1:30 p.m.

1:00-1;30 p.m.

1:00-2:00 p.m.

1:00-2:30 p.m.

1:00-4:00 p.m.

1:00-4:30 p.m.

1:00-5:00 p.m.

1:15-1:45 p.m.

1;15-2:00 p.m.

1:15.2:15 p.m.

1:30-135 p. ni..

1:45-2:45 p.m.

1:45-3:00 p.m.

2:002:10 p.m.

2:00-2:15 p.m.

2:00-2:30 p.m.

2:00-2:30 p.m.

2:003:00 p.m..

2:00-3:30 mm.

2:00-5:00 p.m.

3:00-3:15 p.m.

3;00-3:30 p.m.

3:00-3:30 p.m.

3:00-3:30 p.ln.

3:00-3:30 p.m.

3:00-3:30 p.m.

3:00-4:15 p.m,

3:10-4:50 p.m. .

3:30-4:20 p.m.

3:30-4:30 p.m.

3:50.4:40 p.m: 4:00-4:15 p.m.

4:00-4:50 p.m.

4:15-5:00 p.m.

4:15 p.m. -1:30 a.m.

4:30-5:00 p.m.

4:30-5:00 p.m.

4;30-5:00 p.m.

4:30-5:30 p.m.

4:30-6:00 p.m. -

4:30-7:00 p.m.

4:40-5:40 p.m.

5:00-5:15 p.m.

5:00-5:15 p.m.

5:00-5:30 p.m.

5:00.5:30 p.m.

5:005:45 p.m.

5:00-6:00 p.m.

5:30-6:00 p.m.

5:45-6:00 p.m.

5:45-6:00 p.m.

6:00.6:30 p.m.

6:00`6:30 p.m.

6:00-6:30 p.m.

6'00-6:30 p.m.

6:00-6:50 p.m.

6:007:00 p.m.

1745-2230

1800-1815

1800-1830

1800-1830

1800-1830

18001900 1800-1930

1800-2100

1800-2130 1800-2200

1

¡ 1815.1845

1815-1900

1815-1915

18301835 I 1845-1945

1845-2000

1 19001910 1900-1915

1900-1930

BRT. Belgium

BBC

All India R.

R. Japan -


R. Norway

R. Korea

R. Australia

V. of Nigeria

R. Kuwait

AF RTS-Washington

VOA

Swiss R. International

V. of Revolution, Guinea

R. Bangladash

UN Radio

Sri Lanka Br. Corp.

R. Ivory Coast

' R. Tahiti

R. Japan


1900.1930;R. Afghanistan

1900-2000 B.S.K. Saudi Arabia

1900-2030 HCJB, Ecuador

1900.2200 R. Moscow

2000-2015

2000-2030 2000-2030

2000-2030 2000-2030

R. Japan -

V. of Iran

R. Algeria

R. Korea


2000-2030 Israel R.

2000-2115 BBC

2010-2150 R. Habana Cuba

2030-2120 I R. Nederland

1 2030-2130 V. of Vietnam

1 2050.2140 R. Habana Cuba

2100-2115 R. Japan

2100-2150 R. RSA

2115-2200 BBC

2115-0630 R. New Zealand

2130-2200 R. Canada lnternatiohal

2130-2200 KGEI, San Francisco

2130-2200 R. Sofia

2130-2230 R. Baghdad

2130-2300 t V. of Turkey

2130-2400 AFRTS-Washington

2140-2240 V. of Free China

2200-2215 R. Yugoslavia -

2200-2215 R. Japan

2200-2230 R. Nacional, Venezuela .

2200-2230 i R. Norway

fi 2200-2245 BBC

2200-2300 R. Canada International

2230-2300 Israel R.

2245-2300 I BBC

A

C

A

C

B

B

B

B

C

C

C

i B

C

C

C

C

C

A

C

` 0

A

C

C

C

C

A

B

C

C

B

B

B

c

9505

21590, 17640. 15512

9720,9640,7150 21655, 17755, 15345 (Sun only[ 26040, 21485, 17870, 17710

17830, 11775. (Sat, Sun -1745)

15430, 15330, 11805, 9700 -

11940 (fade-in time varies)

17820,15325- 9505

17900

21480, 17865, 15380

26040, 21590, 21485,

17870, 17710

9795

21620, 21580, 17860, 17850, 11795,

, 17735, 15425, 15360, 15300, 15210

(from April, 1605-1655)

17735 (1610-1655 from May)

1, 15400, 12095 (11820 from 1800)

11620

9505

1 17820, 15260

17755 (Sun only)

9720 11800

15120, 11770

12085

17765, 15430, 15330, 11805, 11790

26040, 21590, 21485, 17870, 17785,

17710, 15445

15305

15310 (varies) (Sun only)

15285, 11765 (both vary)

21670, 19505-SSB, 15410 (Fri)

17850, 15115, 11870

11920

15170, 11825 (exc Sun)

15105

17875, 15325, 11905

17820, 15260

1-1770 or 11820 or 11805

(frequent changes) '

11855

21480, 17865, 15295

9795, 9490 .

15105 0

9022 (frequent time changes)

C 9510

C ,= 11860

A : 17875, 17820, 1-1855

C 1.1655,98t5 A ' 17830, 15260, 6175

A 17855

B 21640,11810,11740.11730 ._

C 15012, 10040

C 17750,9770. 8 ' 15105 -

B - 21535, 17780, 15155

A º

C

B

- C

C

C

C ;

;

i i`

AA

A

2245-2300 UN Radio A

2300.2330 BBC - A

2300-2330

2300-2330 23002330 23002350 2300-2400

R. Japan

R. Sweden

R. Vilnius

Rdif. Argentina

VOA

6:00-7:50 p.m. ' 2300-2450 ; R. Pyongyang

B

C

B

.l C

A

15260, 6175

17770

17875, 17820, 15325, 15150, 01945

15280

11850, 11750

9745

11955,9515,7170,6185 21650, 17765, 15430, 15330, 11790

17890, 15345

9620

17755

15400 (irregular) 15175, 11860 (Sun only)

15260, 11910, 9590, 6195, 6175,

5975 -

15325, 11860

15485;11655,11620,9815 15260, 11910, 9590, 9410, 7325,

6195, 6175, 5975

15225, 11920 (Fri) --

15260, 11910, 9590, 9580, 9410;

7325,^6195, 6175, 5975

17755

11105,9695 7400. 7360, 7215

11710 (Mon -Fri)

26895, 25990, 21610,

21460, 17895, 17820

11535, 9977

t.fi1

Raise the flags of all nations

-

Mq), -c

Mt{dy PTn VIVE

` rr1 W11

5"°194 aeri

1. )-.,%i. ' °' .41,y

1- I

aevotedtoO.Xring

At A supe albut ra

A last- Mg llsignsand

collection of authorised ave stations ,

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Vine -a unique ljeV,Iorld's top shortwave

infoRnationon - o

At last! A superb album

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* Over 30 authorised call signs of the World's top short-wave stations

* Hints on every aspect of the DX hobby

F Recordings to help identify Satellites, SSTV, RTTY, Fax, Time -weather and all other radio sounds

* Talk by BBC World Radio Club's HENRY HATCH

This is your mailing label, please print clearly use plain sheet if you wish to preserve page

IMMEMI 1.111111M Please send records cassettes

Iof "Long Live Short-wave" at £3.50 (56.95 U.S.) ' Price includes post and packing worldwide. U.K price includes V.A.T.

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tctalenclosed US S Or Sterling currency only

NAME (Block Levers please)

ADDRESS

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1 1

-----J CIRCLE NO.65 ON FREE INFORMATION CARD

. ZIP/ Post Code

APRIL 1979 83


SEEKS 1 - ACTIVE

HARD- HITTING

CB DEALERS In return, CPI offers a line

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There is a new ball game at CPI ... DISTRIBUTORS AND MIDDLEMEN HAVE BEEN

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Interested? Fill in and return the coupon.

COMMUNICATIONS POWER, INC. 1280 Reamwood Ave. Sunnyvale, CA 94086 (408) 734-0301

Firm name:

How long in business?

Number: Street:

City: State: Zip:

Name: (if individual)

CIRCLE NO. 10ON FREE INFORMATION CARD

ADVANCED Electronic Music. Products .... effects devices to computer controlled modular synthesizers. Select from experimenter's kits, step-by-step product kits or fully assembled professional equi t.

r L

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"'a

a ` ̀ .1"11" -FREE

color catalog

ELECTRONICS, INC.

1020 W. Wilshire Blvd. OhlahemaCity, OK 73116

SEND FREE CATALOG TO:

name

address

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CIA ELECTRONICS , DEPT. 4 - P

1020 W. WILSHIRE BLVD.. OKLAHOMA CITY, OK 73116

6:00-8:00 p.m. 2300-0100 CBC Southern Service

6:00.9:00 p.m. . - .2300-0200 R. Moscow

6:30-7:00 p.m.

6:30-7:30 p,m.

6:45-7:45 p.m.

7:00-7:15 p.m.

7:00-7:25 p.m.

7:00-7:30 p.m.

' 7:00-7:55 p.m.

7:00.8:00 p.m.

2330.2400 R. Finland

2330-2430 BBC

2345-2445

0000-0015

r 0000-0025

10000-0030

1

0000-0055

0000-0100

7:00-8:00 p -m; ' , 0000-0100 7:00-8:00 p.m. 0000.0100 7:00-9:00 p.m, ' 0000-0200 7:00.9:00 p.m. 0000-0200

7:00 p.m. -1:06 a. m. 0000-0606

7:15-7:30 p.m. 0015-0030 7:15-8:00 p.m. , 0015-0100 7:30-7:50 p.m. - 0030-0050 7:30-8:00 p.m. 0030-0100 7:30-8:00 p.m. ' ` 0030-0100 7:30-8:00 p.m. 0030-0100

7:30-9:00 p.m.

7:30.10:30 p.m.

7:30-12:00 p.m.

7:50-8:35 p.m.

8:00-8:15 p.m

8:00-8:15 p.m.

8:00-8:20 p.m.

8:00-8:30 p.m.

8:00-8:30 p.m.

8:00-8:45 p.m.

8:00-8:55 p.m.

8:00-8:55 p.m.

8;009:00 p.m.

8:00-9:00 p.m,

8:00-10:00 p.m.

8:00-10:30 p.m.

8:00-10:30 p.m.

8:00-11:00 p.m.

8:30-8:50 p.m.

8:30-8:55 p.m.

8:30-8:55 p.m.

8:30-9:25 p.m.

8:30-9:30 p.m.

8:45-9:15 p.m.

9:009:15 p.m.

9:00-9:30 p.m.

9:00-9:30 p.m.

9:00-9:30 p.m.

9:009:30 p.m.

9:00-9:50 p.m.

9:00-9:55 p.m.

9:00-10:00 p.ní.

9:00-10:30 p.m.

9:15-9:30 p.m.

9:30-9:45 p.m.

9:309:55 p.m.

9:30-10:00 p.m.

9:3010:00 p.m.

9:30-10:00 p.m.

9:30-10:15 p,m.

9:30-10:25 p.m. `

9:50-11:00 p.rí1.

10:00-10:15 p.m.

10:00-10:15 p.m.

10:00-10:30 p.m.

10:00-10:30 p.m,

10:00-10:30 p.m.

10:00-10:30 p.m.

10:00-10:30 p.m.

10:00-10:55 p.m:

10:00-10:55 p.m.

R. Japan

R. Japan

R. Tirana

R. Norway R. Peking

VOA

R. Sofia

AFRTS-Washington

Spanish Foreign R.

R. Luxembourg CBC Northern Service

V. of Greece

BRT, Belgium

SOD RE, Uruguay R. Sweden

R.. Prague

R. Kiev

0030-0200 HCJB, Ecuador 0030-0330 BBC

0030-0500

0050-0135 0100-0115

0100.0115

HCJB, Ecuador

TWR-Bonaire

R. Japan

Vatican R.

0100-0120 RAI, Italy 0100-0130 l R. Canada International 0100-0130) V. of Chile

01000145 , R. Berlin International 0100-0155' R. Prague -

0100.0155 , R. Peking

0100-0200 , VOA , 0100-0200 V. of Free China

0100-0300 WYFR, Family Radio


, 0100-0330 R. Australia

0100-0400 AFRTS-Washington 0130-0150 Í V. of Germany

0130-0155 I Austrian Radio " 0130-0155 i R. Tirana

0130-0225 R. Bucharett

0130-0230 - R. Japan

0145-0215 Swiss R. International

0200-0215 r R. Japan -

0200-0230 R. Canada International 0200-0230 r R. Norway 0200.0230 R. Budapest

0200-0230 -R. Warsaw

0200-0250 R. RSA

0200-0255 R. Peking

0200-0300 R. Moscow

0200-0330 ' R. Cairo

0215-0230 ¡ V. of Greece

0230-0245 ' R. Pakistan

0230-0255 ` R. Tirana

0230-0300 % R. Lebanon

0230-0300 t R. Sweden

0230.0300 V. of Chile

0230-0315 R. Berlin International 0230-0325 , R. Nederland

0250-0400 TIFC, Costa Rica

0300-0315 R. Japan

0300-0315-' Austrian Radio

0300.0330 ' R. Canada International 0300.0330. R. Portugal

0300-0330 i R. Budapest

03300.0330 R. Warsaw

0300-0330 r R. Kiev

0300-0355 r R.,Prague

0300-0355 R. Peking

1

i

A 5960 (Mon. -Fri.) (2200-2400 from May)

B - 17720, 15455, 15180, 15140, 12050, 11850, 9760, 9710, 9685, 9665, 9530, 9505, 9490

C 11800, 9565 A 15260, 11910, 9590, 9580, 7325,

6175, 6120, 5975 B 17825, 15270 9 17755 -

B 9750, 7065 C 11870, 9645 (Mon only) B 17680, 15520, 15060 A 25990,21460,17895,1782Ó,15205,

11740,9640,6130 B 9705

A 21650, 17765,15330,11790,6030 B { 11880,9630 C 6090

B 9625, 6195 (not all Eng.) ,

(from May, -0506) 6 11730,9760,9515 C 6080

C 11885, 9515 (time varies) ..

C 11905

C 9630, 6055 B ' 17870, 15180, 12000, 7150,

.

6021159' 5980 A 15115

A 15260, 11750, 9580. 9410, 7325, 6175, 6120, 5975

B_ 11915,9745 B 11925

B ' 17755 . .

B 11845, 9605, 6015

B , 11810,9575 A 17865, 5960 B 11890, 11765

C 11805,9730 B : 11990,9630,9540,7345,5930 B 17680, 15600, 15520, 15060, 12055 A 15205, 11740, 9640, 6130 C 17890, 15425, 15345

A 5985 A 11930

B 17795, 21740

A 21650, 17765, 15330, 17790, 6030 '

A 11865, 9605, 9565, 9545, 6100, ' 6085, 6075, 6040

C . 9770, 6155 B 9750, 7120

11940, 11840, 9690, 9570,

6155, 5990

21640, 17825, 17725, 15195

11780-SSB, 11715, 9725, 9660, 6135 .

B 15105

A 9535, 5960

8 9645, 9550, 6180 (Mob ohly) B 15220, 11910, 9833, 9585, 6105,

6000 (not Mon)

C 15120, 11815, 9525, 6135, 6095 B 11900, 9610, 9585, 5980 B 17680,15600,15080,12055 B 17720, 15455, 15180, 15140, 12050,

12010, 11860, 9710, 9665, 9530,

9490 '

B ' 12050,9475 B 11730, 9760, 9515

C 21590, 17830

B 9750, 7120

C 11785 (frequent changes)

C 11705, 9695 B 17800, 11890, 11765

C 11805,9730 A 9590, 6165 B 5055 B 15105

C 9770, 6155 (Sun only) A 11845, 9605, 9535, 5960 B 11935, 6025 (Mon 0320) B 15220, 11910, 9833, 9585,

1 6105,6000 C 15120, 11815, 9525, 6135, 6095 B 11860, 9780, 9580, 7400,

7245, 6020, 5980

B 11990, 9630, 9540, 7345, 5930

B 17532, 15300, 15060,

12080, 12055, 11685

CIRCLE NO.46 ON FREE INFORMATION CARD POPULAR ELECTRONICS


10:0111:00 p.m. 0300.0400 '

10:00.11:00 p.m. : t 0300.0400

10:00-11:00 p.m. I 0300-0400

10:00.11:00 p.m.- i 0300-0400

10:00-11:26 p.m., 0300-0426

10:00 p. m.-12:15 a.m. 0300-0515

10:00 p.m; -1:00 a.m. 0300.0600

10:00 p.m. -2:00 a.m. ' 0300.0700

10:25-10:30 p.m. 0325-0330 1

10:30-10:55 p.m. 0330.0355

10:30-10:55 p.m. 0330-0355

10:30-11:00 p.m. . I 0330-0400

10:30-11:15 p.m. - 0330-0415

10:30.11:45 p.m._ 0330-0445 t

10:30-11:50 p.m. 0330-0450

10:30.12:00 p:m. 0330-0500

10:30 p.m,1:00 a.m. 0330.0600

10:30 p.m, -12:30 a.m.; 0330-0530 .

11:00-11:15 p.m.

11:00-11:15 p.m.

11:00-11:30 p.m.

11:00-11:30 p.m.

11:00.11:30 p.m.

11:00.11:55 p.m.

RAE, Argentina

R. Baghdad

1113C,, Uganda

R. Moscow

R. RSA

A. New Zealarid

V. of the Voyageur VOA V. of Armenia

R. Tirana

Austrian Radio

R. Australia

R. Berlin International

BBC

R. Habana Cuba

R. Tanzania

R. Habana Cuba

R. Moscow

0400-0415 I R. Japan

0400-0415 ,' R. Budapest.

0400-0430 ' R. Bucharest

0400-0430

0400-0430

04000455

11:00-12:00 p.m. 0400-0500

11:00 p.m. -2:00 a.m. t 0400-0700

11:30-11:55 p.m. 1 0430-0455 ,

11:30-12:00 p.m. f 04300500

11:30-12:00 p.m. 0430-0500

11:45 p.m.12:45 a,m. 0445-0545

12:00.12:15 a.m. 05000515

12:00-12:15 a -m.

12:00-12:30 a.m.

12:00-1:00 a.m.

12:00-2:00 a.m.

12:15.1:15 a.m.

12:22;12:30 a.m.

12:30.12:50 a.m.

12:30-1:25 a.m.

12:30-2:30 a.m.

12:30-7:05 a.m.

12:45-1:00 a.ln.

12:45-2:30 arm.

12:55.3:35 a.m.

1:00-1:15 a.m.

1:00-1:30 a.m.

1:00-2:00 a.m.

1:00-2:00 a.m.

1:00.4:15 a.m.

1:15-1:30 a.m.

1:25-3:55 a.m.

'1:30-2:00 a.m.

1:30.3:00 a.m.

1:403:15 a.m.

1:45-2:00 a.m.

2:00-2:15 a.m.

2:00-4:00 a.m.

2:007:00 a.m.

2:07-2:15 a.m.

2:30'2:45 a.m.

2:30-3:25 a.m.

2:30-4:00 a.m.

3:00-3:15 a.m.

3:30-4:25 a.m.

1 0500-0515

1 0500-0530 ,

0500-0600

10500-0700 05150615 0522-0530

0530-0550 05300625 0530-0730

0530.1205

0545-0600 0545-0730


R. Norway

R. Peking

R. Australia AF FITS -Washington

Austrian R.

Swiss R. International

R. Sof is

BBC

Israel R.

R. Japan

R. Portugal

R. Australia HCJB, Ecuador

Spanish Foreign R.

UN Radio

V. of Germany R. NedeLland

R. Moscow

R. New Zealand

UN Radio

BBC

0555-0835 ' V. of Nigeria

0600-0615 R. Japan

10600.0630 , R. Norway

1 0600-0700 1 RAE, Argentina

0600-0700 R. RSA

0600-0915 i R. Australia


l

0625-0855 V. of Malaysia

0630-0700 R. Korea


0640-0815 ! R. New Zealand


0700.0715 R. Japan

0700-0900 R. Australia

0700-1200 AFRTS-Washington

0707.0715 UN Radio

0730-0745 UN Radio

0730-0825 , R. Nederland

0730-0900 BBC

0800-0815 R. Japan

0830-0925 R. Nederland

9690 (Tue-Sat)

11935

15325 '

12010,11860,9710, 9530, 9490, 7205

11900, 9585, 7270, 5980, 4990

15280

6220

9670, 5995 15180, 12000, 6735 (Sun.,

Wed, Thu, Sat)

7300, 62170 '

9770,6155 17795

11970, 11890, 11840

9410, 6175, 6120 (to 0430),

5975 11930,11725 15435

11760

17870.15455,15140,12050, 12010, 9780, 9505

15105

15220, 11910; 9833, 9585, 6105,

6040 (Wed & Sat)

11940, 11840, 9690, 9570,

6155, 5990

9535, 5960

9550, 6180. (Mon only)' 17532, 15300, 15060, 12055, 11685.

17795,15320 17765; 11805, 11790, 6030

5945

9725, 6045

9530 -

9510, 6175, 5975 (11860 from 05001

15105, 11655, 11620

9505 11935, 6025 (Man -0520)

21680, 17890, 17870, 17725, 15240

6095, 9560, 11915

11880.9630 9540, 6055 (Sat)

11785, 9545, 6185, 6100, 5960

9115, 6165

15140.12050,12010,9780,- 9505,1170 6105 - 9540, 6135 (Sat)

1.1955. 11860, 9640,

9510,-7150, 6175

15120, 11770, 7255

9505

9645 (Mors only) 11755, 9690, 6120 (Tue-Sat only)

17780, 15220

15320 11845, 11825, 9655, 9635

6140, 6045 (Mon -Fri)

15295, 12350, 9750

9640

9525 11945

11845, 11825, 9655, 9635,

6140,6045 (Mon -Fri)

9505 11740, 9570

9700, 9685, 6155. 6095, 6030

9540, 6135 (Sat)

9540.6135 (Tue-Sat)

9770. 9715

11955, 9640, 9510, 7150

9505-

9715

Explanatory Notes.

1. Times in first column are EST (or CDT from April. 291. For AST/EDT, add 1 hour. CST/MDT, subtract 1 hour.

MST/PDT, subtract 2 hours. PST, subtract 3 hours. Days of week are in GMT.

2. Quality. A -strong signal and very reliable reception. B -regular reception. C -occasional reception under favorable

conditions. D -rarely audible. These ratings are for locations in the central USA. European and African stations are in

general, more reliably received in eastern North America. Asian and Pacific :cations are more reliably received in

western North America. North American stations are received well except in areas too close to the transmitter sne.

3. The information in this listing is correct to press time. However, frequencies and schedules are constantly changing.

Listen to "DX Digest" at 1807, 1900 to Europe, Sunday; 0100, 0300, on Monday and 1900 Wednesday to Alrica on R.

Canada International for late changes.

4. R. -Radio; V. -Voice

um am mi um a: imiIN EN mu Ns NE

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J Computer Bits b3p....

LANGUAGE TRANSLATION

MOST OF us remember the various times that Capt. Kirk, in "Star

Trek," used a "universal language translator" to communicate with alien life - forms. Well, such a vocal input/output system has not yet come along, but we are getting closer.

Within a period of three weeks, we had the opportunity to try out two "language translators"-the LK-3000 from Lexicon Corp. (8355 Executive Center Drive, Miami, FL 33166) and the M-100 from Craig Corp. (921 West Artesia Blvd, Compton, CA 90220). The translators are similar in operation though there are minor differences.

Both systems resemble pocket-size

Use Quick -Wedge to fasten leads, wire in panelights, connect test equipment, install components

"k49 I :M.::. 1

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They do all that ordinary screwdrivers do, PLUS they hold and start the screw

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By Leslie Solomon

calculators and have alphanumeric key- pads, and ,16 -digit multi -segment displays. The Lexicon uses LED's while the Craig uses fluorescent readouts.

These machines have English as their "base." In operation, an English word is entered on the keyboard, a switch is de- pressed and both the English and its equivalent in the other language appear in the display. It is also possible to enter the foreign language word and have the display give the English equivalent. Both are provided with about 1500 commonly used words (similar to those little travel books tourists carry), and both also contain 50 or so of the most frequently used phrases. Foreign languages include

LEXICON LK-3000 IRI

French, Spanish, Italian, Portugese, etc., with Japanese, Russian and others coming soon. If an expression is longer than the display, the words will scroll left to allow the message to pass along.

Both machines are provided with plug-in modules that are used to change languages, and are in the $225 catego- ry. They also provide simple calculator operations and can provide a "menu" of the data within their ROM's.

Electronically, both are basic computers in that they contain a processor, some RAM and have their language in ROM. The processor has the usual support circuitry and includes the 16 character display. The M-100, for example, uses a 3870 CPU, features 16K bits of internal ROM (carrying housekeeping and English), and can support 32K or 64K of plug-in ROM carrying the other language and data.

Everything is done in software (actually firmware) and both use proprietary programs. In both cases, the plug-in ROM will be sold over the counter. (Craig is asking $25 per language.)

Engineers for both companies refused to speculate on vocal input/output at- tachments for their devices, so we still have something to look forward to be -

7 MET US XOM K 9 c - X

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The Lexicon LK-3000 language translator uses LED readouts.

The Craig Model M-100 translator uses a 3870 CPU.

POPULAR ELECTRONICS


fore we can join Kirk in his galactic conversations.

Atari Steps In. After several years of

being one of the leaders in making ar-

cade and home video games, Atari Inc.

is now offering a pair of personal computers. One is the Atari -400 (approximately $500) using a 6502 CPU, 8K of

RAM and 8K of ROM (expandable to

16K). The keyboard is a 57 -key Mono -

panel with fingertip touch -contact points rather than mechanical keys. The sys-

tem has upper and lower case, graphics and screen editing functions. Up to 40

characters on 24 lines can be displayed on a conventional TV. Up to 16 colors and 8 luminance levels are provided.

A built-in r -f modulator, set to either channel 2 or 3, conforms to the FCC

Type -1 specifications. R -f radiation is

kept down by using an extruded metal shield to cover the complete system (un-

der a plastic cover). BASIC is provided. A special I/O connector allows interfacing to the several peripherals Atari in-

tends to provide. Special input jacks, lo-

cated under the keyboard on the front,

allow use of game -playing controllers. (Continued on page 88)

Economics /a the tree of .octal Telenet which des le with:

- Production - Distribution - Coneueotlon

It /a sometimes called:

'Political Econona'

Economics may be Ignored, until dlntuebancee occur which affect

our Proaoeritti. or our jobs.

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The Atari -400 personal computer uses a 6502 CPU, 8K of RM and SK of ROM. Keyboard is a 56 -key Monopanel with, touch -control points.

Featuring -

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In fact, not only will ye. now be able to use a personal computer creatively,

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Plug in the GIANT BOARD to record and play back programs, edit and

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ELF II add-ons already include the ELF II Light Pen and the amazing ELFBUG

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The ELF -BUG Monitor lets you debug programs with lightening speed because

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The incredible ELF II Light Pen lets you write or draw anything you want on a

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ELF II Tiny BASIC Ultimately, ELF II understands only machine language -the fundamental coding

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Tiny BASIC saves you the time of having to code your individual instructions in

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Now Available! Text Editor, Assembler, Disassembler And A New Video Display Board!

The Text Editor gives you word processing ability and the ability to edit

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ELF ll's Assembler translates assembly language programs into hexidecimal

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ELF It's Oisassembler lakes machine code programs and produces assembly

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The new ELF 1I Video Display Board lets you generate a sharp, professional

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O Teal Editor on cassette tape gives you the abdtty to

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Coming Soon: A -O. 0-A Converter. Controller Board

and more.

mini Name

Address


APRIL 1979 87


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1

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(Continued from page 87)

The cassette player used with the system has no volume or tone controls, but does have a tape counter and pushbutton controls. It is also operated by the computer. Digital data is on one track, while audio is carried on the other. Data transmission is 300/600 baud, software controlled. Atari supplies a complete line of software, including many games.

The second system, the Atari -800 (approximately $1000), has all the electronic features of the 400 and comes with 8K of RAM plug-in expandable to 48K. It too comes with BASIC in ROM. This system can drive up to 4 disks and a printer. Soon to be available are an acoustic modem, a direct telephone adapter,- an ac controller, a light pen, voice synthesizer and recognition, and a music synthesizer. Atari also supports this system with a full line of software (interchangable with the 400). Lan- guages include BASIC and DISK BA- SIC, with other languages under consideration. They also hope to have an assembler, disassembler and text editor.

Each of the plug-in modules (RAM and operating system) is protected by a plastic enclosure. Details of the 44 -pin bus were not available.

The keyboard features 57 full -stroke mechanical keys and four separate function keys. It too has a built-in modulator. Besides its built-in speaker, the 800 also provides TV sound.

The 40 -column printer uses dot matrix and standard paper rolls and ribbons. It

hándles 40 characters per second and one line per second. It contains its own processor. The 800 can handle up to four disks simultaneously. The disk system uses standard 51/2" diskettes with 92K per side and also contains its own processor. The various peripherals are "daisy chain" coupled to the single output connector.

TRS-80 S100 Adapter. The 8100, an S100 bus adapter motherboard, plugs into the TRS-80 via a ribbon cable. The 8100 also features 6 slots and card guides, and a second TRS-80 connector allows other TRS-80 devices to be connected at the same time. The new motherboard has optional on -board circuitry and sockets for 16K of dynamic RAM, I/O interfaces for serial and parallel I/O both RS232 and 20-mA loop and an 8 - bit parallel I/O port. The basic unit, including the S100 bus interface, one edge connector/card guide set, and manual is $185 per kit and $245 assembled. Five connectors/card guides are $45 as a kit, $75 assembled. The RAM

support option (less RAM's) is $45 kit and $75 assembled, while the I/O option is $85 kit, $115 assembled. HUH Elec- tronics, 1429 Maple St., San Mateo, CA 94402 (Tel: 415-573-7359).

Apple Robot. If you have an Apple II, the addition of ROBOT 1, will enable you to control a battery -powered car merely by speaking the words "forward," "reverse," "stop," "left," "right," and "straight". The ROBOT 1 plugs into an Apple slot, and the accompanying program is run. The speech system uses the Heuristics Model 20A Speechlab. The radio link is effective to about 300 feet. The system comes with car, radio - link controller, Apple II peripheral card, preprogrammed demonstration tape and instruction manual. Heuristics, Inc., 900 San Antonio Rd, Los Altos, CA 94022 (Tel: 415-948-2542).

New Computer Clubs. An 1802 user group is now in operation in Finland. Contact: J. E. Nystrom, Ulvilantie 2 C 27, SF -00350 Helsinki 35, Finland.

A new Canadian club has also been reported. Contact: West Coast Comput- er Society, POB 4476, Vancouver, B.C., Canada V6B 3Z8. o

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88



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e

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most advanced oscillo- f e 7 - scope Heath has ever ! developed. Compare

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a iy :2:15 ;i -

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Plus hundreds of top -performing, value -priced electronic kit products for home, hobby or business. See the most powerful personal computer systems you can buy with complete software and peripherals. See the Heathkit Continuing Education Self -Learning Programs in Basic and Advanced Electronics, Automotive Electrical, Test Instru- ments and Novice and General Amateur Radio Licenses-the most efficient and economical way to stay on top of our electronics world! FILL-IN COUPON AND SEND TODAY.

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Every Heathkit product is backed by world-famous technical service and counsel - plus sales and service facilities at 54 Heathkit Electronic Centers* coast -to -coast (*units of Schlumberger Products Corporation). See the white pages of your phone directory for the center nearest you.

APRIL 1979

r

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nel-management system which can produce paychecks. W-2 forms, and reports. MI- CROINV carries out inventory -control functions, including analysis and order -quantity suggestions. Programs are available for Mi- cropolis or Cromemco 16K BASIC. Packages with listings are $120 per program; Micropolis II disks, available to package buyers only, are $10 each. CompuMax Associates, 505 Ha- milton Ave., Palo Alto, CA 94301.

North Star Applications Soft- ware. Three diskettes of programs (one each financial, mathematical analysis and statistical) from the Osborne book "Some Common BASIC Programs" two game diskettes, one diskette each of backorder, retail sales -report and mailing -list programs using disk data files, and a Northstar DOS for Cen- tronics printers are now available from Arizo- na and Dallas Byte Shops, or from MicroAge. $35 per diskette. MicroAge Mail Order, 803 N. Scottsdale Rd., Tempe, AZ 85281.

CP/M Users' Group Programs.For a $4annual membership charge,CP/M users can have access to hundreds of programs for $8 per diskette, with an average of about 17 programs per disk, or 50 cents per program. Pro- gram disks available include utility, game, in- structional, general ledger, math, monitors, and such languages as BASIC -E, PILOT, AL- GOL -M, STOIC, and CASUAL. CP/M Users' Group, 164 West 83rd St., New York, NY 10024.

SC/MP Cross -Assembler for 8080. Systems capable of running the ASM80 mac- roassembler for 8080 can now be used to develop programs for the National Semiconduc- tor SC/MP (INS8060). The cross -assembler program, MDSMAC, consists of a set of mac- ros loaded into the host system assembler's macro tables. Paper tape, $5.00. National Computer Users Group, National Semicon- ductor Corp., 2900 Semiconductor Dr., Santa Clara, CA 95051.

8080 Development Software and Aids. Tychon, whose principals edit the popular 8080 Bugbooks, also offers two pro - gams and two versions of a programming aid for 8080 users. The TED editor and TAS assembler accept both octal and hex values and yield octal or hex program listings from either input. The package has its own reloca- tor, character string search, and occupies less than 5K. The standard version, with relo- cator, addressed at 00, is $35 for a paper tape and manual; it's also available custon. assembled to any address for $50. Hex or octal listings are $30 each. DBUG: An 8080 In- terpretive Debugger allows programs to be entered, changed, and single -stepped, and displays registers at breakpoints. It resides in 1K. DBUG tapes are $10, and documentation is $4.95. DBUG listing book from Howard Sams (order # 21536), 4300 W. 62, Indi- anapolis, IN 46268; other items from Tychon, Box 242, Blacksburg, VA 24060.



PROJECT OF THE MONTH

EXPERIMENTAL SOLID-STATE

OSCILLOSCOPE

In the October 1978 Experimenter's Cor- ner I made a brief reference to an experimental solid-state oscilloscope that employs, as a display screen, the 160 -element LED array that appeared as the last

Project of the Month. Many readers have written requesting additional information, so here it is!

Figure A is the schematic diagram of the experimental scope. In operation, a signal applied to the noninverting input of the 741

op amp is amplified and routed to a flash A/D converter made up of LM339 quad comparators and a 74147 priority encoder. A detailed description of this A/D converter was given in the September and October 1978 Experimenter's Corner columns.

The digital output of the 74147 is a 4 -bit

/0400/ +SV

_

I I. -

0 ---9V VER TICA L

LA/N

/oo.n

IX

/K

IR

It

/K

/K

BCD nibble. This nibble, after being decod-

ed by a 74145 1 -of -10 decoder, activates one of the ten horizontal rows of LEDs.

One of the sixteen vertical columns of

LEDs is activated simultaneously by a hori-

zontal scanning circuit consisting of a 555

timer, 74193 4 -bit counter and 74154 1 -

of -16 decoder. The 555 serves as a time

base whose sweep frequency is controlled by a 1-megohm potentiometer. The 74193

and 74154 form a 0 -to -15 sequence generator that sweeps the sixteen columns of

LEDs one at a time. Because only one row and one column

of LEDs are activated at any time, only one

LED in the array glows at any single in-

stant. When the sweep rate is faster than

20 or 30 complete scans per second, the

individual LEDs merge into a broken line

that provides a rough pictorial representa-

tion of the positive half of the waveform ap-

pearing at the input of the 741 op amp.

Three of the gates in a 7400 quad NAND

gate add a simple but very useful trigger feature. When pin 14 of the 74193 is

grounded by placing the MODE switch in its

FREE RUNNING position, the sweep circuit

scans the LED columns continuously. A

A11 CONo RA7-aR5 //4 LM339

5 I /0 '7> 1

a

1 S

/43 3 z

2 /

®/3 //

11

6

S

7

B

9

6

7

1\t 3n.3011

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careful adjustment of the time base poten-

tiometer will freeze the waveform being displayed. Any drift, however slight, in the

incoming waveform will require a readjust- ment of the time base. Otherwise, the

waveform being displayed will move

across the screen from left to right or right

to left, as it did before the potentiometer was adjusted.

When the MODE switch is placed in its

TRIGGERED position, pin 14 of the 74193 is

reset (or cleared) to 0000 when an input

signal is not present. An input signal with

enough amplitude to activate the lowest -

order LM339 comparator causes pin 6 of

the 7400 to go from high to low. This allows

the 74193 to make a complete scan of the

display columns. If the input signal ís still present when

the scan is completed. another scan is im-

mediately begun. Otherwise, the scope

waits for the signal to recur before initiating

a new scan. The result is that in the trig-

gered mode the scope automatically locks

onto a recurrent waveform, and displays it

with its rising portion originating in the first

column of LEDs. A LED connected to the

trigger gate network indicates when trig -

/0 X /6 LEO ARRAY

33031

33011

9

2

//1l 6 TR/GOEREO -1-- -

* 5 V MODE

TR/í-ER - _ FREE RLNN/NG

2 7400

Tyo/GAL ARR Ay CONNECT/ON

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79/93

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Fig. A. Schematic of a solid-state 10-4 -16 LED a Tray oscilloscope.

APRIL 1979 93


Project of the Month continued

gering is occurring, which might not be known if the gain is set so high as to prevent observation of the waveform.

When the scope is in the triggered mode, the waveform being displayed can be expanded or compressed by changing the horizontal sweep rate. Similarly, the height of the waveform can he increased or decreased by adjusting the VERTICAL

GAIN potentiometer. An overrange LED connected to the output of the highest - order LM339 comparator indicates when the gain is too high and the top of the waveform is therefore off the screen.

Although it is considerably easier to assemble the drive circuit than the LED display board described last month, care must be exercised when building it because wiring errors can be very difficult to find. I assembled the prototype driver circuit on the same kind of board used for the display (Radio Shack 276-152 or similar) using wrapped -wire, point-to-point construction. Figure B shows how the major components were arranged on the top side of the hoard. Note the miniature phone jack that serves as the vertical input for the scope. This jack should be installed from

COM aARgrOR RES/STORS

RES roe 5s PNONE ACK

(ACE55/BL E FROM BACK OF 8OA<D)

the front side of the board. After the components on the board are

connected together, connections to the display board, the time base potentiometer, the vertical gain potentiometer and the power supply are provided by soldering wrapping wire to the appropriate copper fingers on the board.

Last month, the bus locations I used on the display board were given. The bus locations used for the remainder of the scope circuit are as follows: Oscilloscope Circuit S-44 Socket -.-5 volts 1

Ground 2

Overrange LED Cathode 3

Vertical Gain Control M

Vertical Gain Control N

Horizontal Sweep Control S

Horizontal Sweep Control T

Mode Switch: Pin 6 7400 Ground Pain 14 74193

Trigger LED Cathode -9 volts

9 volts

U

V

W X

Y

Z Don't feel compelled to use these bus lo-

OO LM 339

o o o o o o

N 339

LM339

C74 I

--.-A- 0 O

0.1

¡ 74i47

r 7'/04 I

74/45

7404

.2X22- CONNECTOR

755

74/5 t

E06E C.4RD

cations. All of them can be changed so long as they don't interfere with the display bus. It's a good idea to reserve the 1, 2. Y

and Z locations for the power supply since these are closest to the two copper strips that traverse the perimeter of the circuit boards. You can use a small file to separate these into four separate strips.

After the scope circuit has been completed, saw off the upper portion of a second circuit board and install a power switch (3PST), trigger mode switch (SPDT), trigger LED and vertical gain and horizontal sweep rate potentiometer. Figure C shows the layout I used to make the prototype. This board becomes the control panel for the scope. Its components should be connected to the appropriate copper fingers in

accordance with the bus given above or the one you select.

You'll need to make a card rack or mother board to hold the three boards that com- prise the oscilloscope. If you can afford a

commercial mother board, great. If not, do what I did and attach three 44 -connector sockets with wire -wrap terminals to a couple of wood or plastic rails. Mount the sockets an inch apart from each other. Next,

Fig. B. Layout of the major components of the experimental oscilloscope on a 2 x 22 connector edge hoard.

Fig. C. Prototype la gout for the control board for the

LED oscilloscope.

/- 5/8"

SHIN POT TRIGGER LED r- 3/8°

SWEEP Por

ON-OFFiO V OR TR/GGER sky/m/-1 4 \ MO DE

S up, TCN

o

1111111l111111 1i1 I I 1



connect all the common connectors with

wrapping wire. Then insert the scope card

in the rearmost socket (ICs facing for-

ward), display card in the center socket and control card in the foremost socket.

The prototype scope is powered by two

9 -volt batteries and a 6 -volt battery made

from four AA alkaline cells in a plastic hold-

er. The batteries are connected to the

scope with three battery connector clips. Before applying power to the circuit, be

sure to take the time necessary to retrace

all the wiring to make sure you've made no

errors. The most common problem in a

project using wrapped wiring is overlooked connections, particularly those to the pow-

er supply pins of the ICs.

Make a probe for the scope from a

length of flexible shielded cable, a minia-

ture phone plug, a test clip and an alligator clip. For initial tests, use a ramp or triangle

(A) TYPICAL RAMP Ba D/SPLAYED ON /60-ELEMENT LED SCREEN

Once you have the scope working, you'll

be able to display a variety of waveforms

after a little practice. Spikes, triangles and

ramps are the waveforms best repro-

duced. Sine waves are slightly distorted by

the low resolution of the screen, and the

rising and falling portions of square waves

are usually very faint. Often several LEDs

in a vertical column will appear to be on as

shown in Figure D, but it's usually possible

to resolve the general waveform being dis-

played. Although the resolution of this experi-

mental scope is poor and the design of the

vertical section leaves much to be desired, it does demonstrate that a flat -screen,

compact oscilloscope can be built. If you

build the scope you'll want to spend some time calibrating the vertical and horizontal

sections with the help of a voltmeter and

frequency generator or a conventional os -

Fig. D. Portions of two waveforms as displayed on 160 -element LED displa y.

wave having an amplitude of Up to a few

volts and a frequency of a few hundred hertz. Be sure to perform the tests in a

darkened room, at least initially, since the LED array will not be as brightly illuminated as a conventional CRT screen.

If the scope fails to respond, make sure that power is being applied properly. Then try changing the gain and time base settings as well as the trigger mode. If the

scope still does not work, you will have to

troubleshoot the circuit. Hint: Proceed one

step at a time. For example, troubleshoot the sweep circuit by beginning at the 555 (is it pulsing?). Then move to the 74193 (is

it counting?), etc.

a tel

ezo VERY D/M --

(6) TYP/CAL SQUA.PE /Vf7VE

cilloscope. You might also want to modify or try to improve the design if you're ex- perimentally inclined. The A/D converter of the vertical section, for example, can be

greatly simplified by using a single -chip A/D converter. The sensitivity of the vertical Comparator string can be varied by re-

placing the 1-megohm resistor at the top of

the voltage divider with either a fixed resistor having a different value or, better yet, a

1-megohm potentiometer. Similarly, a wide range of sweep rates can be obtained by

replacing the single timing capacitor with a

group of fixed capacitors of various values, one of which would be selected by a rotary switch. O

APRIL 1979

FREE WTI CATALOG Audio-Computers

Instruments Kits & Assembled

South west Technical Products Corporation 219 W. RHAPSODY

SAN ANTONIO, TEXAS 78216

a_ CIRCLE NO.52 ON FREE INFORMATION CARD

Put Professional Knowledge and a

COLLEGE DEGREE in your Electronics Career through

HOME tá STUDY , :Valk

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The Grantham electronics degree program begins with basics, leads first to the A.S.E.T. degree, and then to the B.S.E.T. degree. Our free bulletin gives complete details of the program itself, the degrees awarded, the requirements for each degree, and how to enroll. (We are located at 2500 S. LaCienega B1., Los Angeles, Calif.) Write to our mailing address shown below for Bulletin E-79.

Grantham College of Engineering P. O. Box 35499

Los Angeles, California 90035

Worldwide Career Training Uiru Home Study CIRCLE NO.25 ON FREE INFORMATION CARD


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Contacts 22 PIN 24 PIN 28 PIN 40 P I N

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GENERAL INSTRUMENT 1 Amp Rectifiers (Epoxy) Pad No. Price 1144001 50V .029 1N4002 100V .039 1N4002 200V .045 1N4004 400V .049 1N4005 600V .055 1N4006 800V .065 1N4007 1000V .07

SWITCHING DIODES

1.5 Amp Single Phase Silicon Bridge Rectifiers

Part No. Price WO6M 600V .34 WO8M 800V .39 o Part No.

1N914 (100V 4NS) 1N4148 (100V 4NS)

Price

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.027

L. E. D. LAMPS LED209 T-1 3mm Red .09 LED211 T-1 3mm Green .14 LED212 T-1 3mm Yellow .13

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LINEAR I.Ct.'S LM324N .49 LM339N .49 L M 555N -8 .29 LM556N-14 59 LM723CN .34 LM723CH .39 LM741CH .37 LM741CN-8 .24 LM 1458N -8 .39

Quad Op Amp Quad Comparator Timer Dual Timer Voltage Regulator Voltage Regulator Op Amp Op Amp Dual Op Amp

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54.95

55.75

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LM323K

78H05KC

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51.60

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79000C Series 51.10 TO.2201 LM 320T

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7900KC Series 51.95 TO-31LM320K

78MGT2C 51.25

78GUl 10.220 51.45

78540PC 52.50

DESCRIPTION

3 Amp 5 Volt Regulator

5 Amp 5 Volt Positive Regulator TO3 Positive Voltage Regulators (Plastic) 1 Amp 5.6, 8. 12. 15. 18, 24 Volts Positive Voltage Regulator 1/2 Amp 5,6.8.12. 15. 18.24 Volts

Positive Voltage Regulator 1 Amp 5. 6.8. 12. 15, 18.24 Volts

Positive Voltage Regulator 100 MA 2.6.5, 6.2.8.2. 12, 15 Volts

Negative Voltage Regulator 1 Amp 5.6, 8. 12, 15. 18, 24 Volts

Negative Voltage Regulator 1/2 Amp 5.6.8, 12. 15.20.24 Volts

Negative Voltage Regulator 1 Amp 5.6.8.12. 15. 18.24 Volts

Dual In Line Adjustable 4 Terminal Positive Voltage Regulator

1 Amp Adjustable Positive Voltage Regulator

Switching Regulator

All new major manufacturer production material offered.

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5.95 9.95

14.95

3.50 3.95 3.95 4.95 4.95

$10.90 S13.10

$32.20

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$45.00 $50.00

MOS Static RAM's Part No. Price

2102LFPC $1.19 1K 35ONS (Low Power)

2102-1 PC $.99 1K 450 N S

2114 $7.50 4K (iK x 4) 300NS

2114 $6.50 4K (1K x4)45ONS

MOS Dynamic RAM's Part No. Price

4K 4027 $2.95 4K (4K x 1) 300NS 16 PIN

416-3 $9.95 200N5

416-5 $7.95 300 N S

UART's Part No. Price

AY5.1013A $4.95 AY3-1015 $5.95

1K CMOS RAM Part No. Price 5101 $4.95

450NS (Low Power)

5101 $3.95 BOONS

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V. ISA ~MI



4 THE MOST ADVANCED TIMEPIECE 4 OF ITS KIND IN THE WORLD! 4 LCD Quartz Alarm Chronograph with calen

dar and dual Irme zone!' Watch is the same as . Seiko but you pay a lot more for the name! Features

4 4 I 4

_ " S65.50

4 o.., , ae r or.i wnwRaNrel

ELECTRONIC DOOR GUARD This is an advance unit using CMOS I.C. and digital parts. You simply mount the unit on the door and the magnetic switch will turn the unit on to make a charming "Ding-Dong" sound

v aT when someone comes in. A presetable 3 -digit digital. security system circuit allows you to set the unit on "guard" when an unexpected person opens the door. The siren alarm will sound and cannot turn off without the correct 3 -digit combination. Uses 9V battery (included). Completed unit, not a kit.

FORMULA

aaaAa

JUMBO 1" LED ALARM CLOCK MODULE

Transformer 51.75

/ , '/

.. ik:., Stereo level indicator kit with arc -shape dis-

play panels! This Mark Ill LED level indicator is a

new design PC board with an art -shape 4 colors LED display (change color from red, yellow, green and the peak output indicated by rose red). The power range is very large, from -30rIB to t5c1B. The Mark Ill indicator is applicable to 1 watt 200 watts amplifier operating voltage is 3V 9V DC at max 400 MA. The circuit uses 10 LEDs per channel. It is very easy to connect to the am plifier. Just hook up with the speaker oulputI

IN KIT FORM S17.50

I0t,r41

S29.50

PROFESSIONAL CASE for our 0-30V Power Supply. It is a nice looking metal cast case with giant 4" volt/amp meter; output binding post and fuse holder, on/of switch and line cord! ONLY $21.50 EA.

POWER SUPPLY KIT 0-30V D.C. REGULATED

Uses UA723 and ZN3055 Power TR output can be adjusted from 0-30V, 2AMP. Complete with PC hoard and all electronic parts. $10.50 each

Transformer for Power Supply, 2AMP 24V x 2 $8.50

9 STEPS LED LEVEL INDICATOR KIT

'y

1t 1 1 ,1 1

for most stereo amplifiers This new protect works as a pair of VU meter to indicate the output evel of your amplifier from -20dB to +34:16. Kit includes all LED, transistors, electronic components, P.C. Board and instructions.

Easy to build and fun to see. ONLY $12.50 EA.

A NEW SOW 4: SOW -

COMPLETE STEREO AMPLIFIER

With all tone control and a new Cli) desgn. Bi-Fet Front Amp will be

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, Completed Unit, Not a Kit! Order Now.

SANYO HYBRID Audio power amplifiers I.C. Max. hi-fi output power, minimum ext. components needed.

SONY Q STN056.

15 Watts STK-028 5 8.50 23 Watts STK-054 513.50 30 Watts STK-056 517.50 50 Watts STK-050 $26.50 10W e COW Istereol STK-040 514.50 15W - 15W Istereol STK-041 525.50 20W + 20W Istereol STK-043 $31.50

'data sheet comes with purchase

1Watt AUDIO AMP All parts are ore assembled

on a mini PC Board Supply Voltage 6 9V D.0 SPECIAL PRICE S1.95 ea.

SW AUDIO AMP KIT

Illllll I

= 2 LM 380 with Volume Control Power Supply 6-18V DC

ONLY S6.00 ea.

ULTRA SONIC SWITCH KIT

4

1

'1

:

ELECTRONIC DUAL SPEAKER PROTECTOR

Cut off when circuit rs shorter! or Over load to protect your amplifier as

well as your speakers. A must for OCL circuits.

KIT FORM 58.75 EA.

FM WIRELESS MIC KIT It is not a pack of cigarettes. II is a new FM wireless mic kit! New design PC

board fits into a plastic cigarette bon. (case included) Uses a

condensor microphone to allow you ro have a

better response in ' sound pick-up. Trans. - ,n ., TITS up to 350 III With 9';, an LED mdreator to

signal the unit is on. KIT FORM

$7.95

60W + 60W STEREO AMPLIFIER

1.111111111'.3111i.i11Ir

`'1' 'Iv- Ill At?

1^' I

COMPLETED UNIT -NOT A KIT! OCL rear amp. 8i low noise pre amp. with bass, middle, treble 3 -way tone control. Fully assembled and tested, ready to work. Total harmonic distortion less than 0.5% per channel at 812 .

Power supply is 36V 3A AC or DC. Complete unit assembled and tested S49.50 ea. power transformer S 9.50 ea.

4 4 Ti -P

4 r

414

4 15

Assembler) not a kill Features ' 1" 4 digits red LED display

' 12 hours real rime. format 24 hours alarm audio output (lust add speaker) Power failure indicator Count Clown timer 59 rains.

12 16V AC 50'60 Hz inpu t 10 min. snooze con. 1,01

S8.50 EACH

5

24 hour alarm Chronograph Counts up to 12 hrs., 59 miss. 59.9 sec. Precision of ctsrOno up to 1/10 sec indicated by 10 moving arrows!' Lap troll. (with chrnno run. ping unlnterr upterl) Time displays by LCD for hour, min sec, 'lay. date of the week and AM/PM.

' Calendar grves orn dateday ' Dual time zone for any two

cities of the world at your. own choice. Wrth light switch to allow you to see the time in the dark!

BATTERY POWERED FLUORESCENT LANTERN

FEATURES Circuitry' designed for operation be high erf¡ecient, high power silicon transistor which enable alumina -

Lion maintain in a standard level even the battery supply drops to a certain low voltage. 9" 6W cool/daylight miniature llourescent tube. 8 X 15V UM.1 (size D) dry cell barters. Easy biding door for changing batteries.

s10.50 EACH Stainless reflector with wide angle increasing lumi Al MODEL 888 R nation Of the lantern. ..................

4111 FORMULA INTERNATIONAL INC. I4 . 12605 CRENSHAW BOULEVARD HAWTHORNE, CALIFORNIA 90250

For more in /ormanon please cap (2131 973.1921. (2 131 6/9-5162

charge master

Kit includes the Ultra Sonic Trans- ducers, 2 PC Boards for transmitter and receiver. All electronic parts and instructions. Easy to build and a lot of uses such as re-

, mote control for TV, garage door, alarm system for counter. Unit operated by 9-12 DC. S15.50

ELECTRONIC ' WHEEL OF FORTUNE KIT

'filth 10 numbers split into black and white on drat, The LED ¡urns when you hit the P ay switch. when it slows down and stops ryr nne number II sounds like a moro,

.r.L 5u there is none. Lots of fun and easy to bum Kit comes with nice looking case, all

*444 . electronic parts. P.0 Board and LEDs. Bertery not in eluded 512.50

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SEND $1.00 FOR DETAILED CATALOG

APRIL 1979 CIRCLE NO.22 ON FREE INFORMATION CARD

97


Transistor Checker MICROPROCESSOR COMPONENTS

*

- Completely Assembled - - Battery Operated - The ASI Transistor Checker is cap. able 01 checking o wide range or transistor types, either "in circuit" Oe Out of circuit. To operate, imply plug the transistor to be

checked Into the front panel socket, or connect it with the alligator clip test leads provided. The unit safely and automatically identifies low, medium and high. power PNP and NPN transistors. Sleet 310" e 674" x 2" "C" cell battery not included.

TransCheck $29.95 ea. Custom Cables & Jumpers

DB 25 Series Cables Part No. Cable Length Connectors Price 0625P -4-P 4 Fi. 2-0P25P S15.95 ea. DB25P-4-S 4 Ft, 1-DP25P/1-25S S16.95 ea DB25S-4-S 4 ft. 2-DP25S S17.95 ea.

Dip Jumpers 0J14-1 It. 1 14 Pin 51_59 ea. DJ16-1 ft. 1-16 Pin 1.79 ea.

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0J24.1-24 Ii. 2-24 Pin 4 95 ea. For Custom Cables 6 Jumpers. See JAMECO 1979 Catalog for Pricing

15, CONNECTORS icansomnpal 25 Pin -D Subminiature

D1325P (as pictured) PLUG (Meets RS232) 52.95 DB25S SOCKET (Meets RS232) 53.50 DB51226-1 Cable Cover for DB25P or DB25S 51.75

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80804 8212 8214 8216 8224 8226 8228 8238 8251 8253 8255 9257 8259

8080A18080A SUPPORT DEVICES MICROPROCESSOR MA8UALS CPU S 9,95 M-280 User Manual 8'Brt Input/Output 3 25 M-COP1802 User Manual Pronto Interrupt Control 5 95 01650 User Manual Ili -Directional Bus OrNer 3.49 Clock Generatot101,cer 3 95 ROM'S

MC6800 MC6a02CP

MC6810API MC6B21

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2400 bps Modulator 14.95 528072101 409601 Oval 3Slate Bus. Trans. (MC81261 2.25 7489 ION

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Static

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51.49 99

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1.95

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4.95 175 4 95 3 95 4.95

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"Regaites 3 Nonce. -5V, -5V. -126 5203 2048 RAMOS 1495 6301.1176111 1024 Tnstate BrpoHw 349 6330-1176021 255 Open C Biodor 2.95 82627 7208 Open Colima, 3 95 825115 4096 Bipolar 1995 825123 3208 Latate 3 95 74186 512 TTL Open Co lector 9.95 74186 256 TTL Open Cmleotor 395 745267 1024 Stack 2.95

The Incredible

"Pennywhistle 1031"

$139.95 Kit Only F, ja The Pnnrwhltlle 103 n capable of recortang data to and Rom New rape without critical Speed eeOunements Nr Ire recorder and it is able to communicate directly with

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serectablel Meaimum gala Rate 300 Baud Data retool Asynchronous Sinai (alum to mate levelteSulred

between ear nerl Receive Channel Fries 2025 Ht IOr space, 2225 He for mars

Transmit Channel Frequencies Switch selectable Low Plenal) 1070 space 1270 mare Nigh 025 Space, 2225 mirk

Receive Sentllirny 46 diem Acoustically coupled Transmit Level -15 dbm nominal Adjustable from -6 dbm

to -20 dbm Receve Frequency Nieman, ._Frequency reference asromat,sally aOlusls to

ow ter Openlion between 1800 Wand 2400 Ht Digital Data Intenace SIA 415.232C or 20 mA currant loop Incener ,o

oDlmsolated and ron.DOUrl Power Resunemenls 120 VAC, single etase, 10 Want. Physical All components mount on a single 5' by 9'

printed urcurt boato Ail components Incruded Reveres a VOM, Audio 0ffnaio, Frequency Counter andmr OSrmascooe to align

TRS-80 16K Conversion Kit Expand your 4K TRS-80 System to 16K. Kit comes complete with:

8 each UPD416 (16K Dynamic Rams) Documentation for conversion

TRS-16K $115.00 Special Offer - Order both your TRS-16K and the Sup'R' MOD II Interface kit together (retail value $144.95) for only S139.95

0.4 volts

100mA

41 MW

Solar Cells 2x2cm

Can be added in series for higher voltage or parallel for higher current.

#SC 2x2 S1.95 ea. or 31S5.00

Magnetically Activated

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G=G CONTINENTAL SPECIALTIES

PROTO BOARDS Proto Board 203

Model Number

P9-6 PB-100 P8-101

tamo r

log T

noslt 1.1 ranos

24-11 pin DOI

one

a S rer

Pe 203 575.00 LaWaH ¡Inches)

6.004.5014 60045014 6.0x45a14

Price S15.95 519.95 522.95

Pro o Board 2034

Model Number P8.102 PA .103 P9104

v0c woe 1-.p.nra. ontu .1171131

oc . Is

v0c

NM WY,

óán

4. -15 Twnw4 0 v .r

o3aA

PB203A $124.95 LaWxH (Inches)

7.0e4.581.4 9086081.4 9888081.4

Price 526.95 544.95 554.95

COMPUTER CASSETTES . 6 EACH 15 MINUTE HIGH

QUALITY C-15 CASSETTES . PLASTIC CASE INCLUDED

12 CASSETTE CAPACITY . ADDITIONAL CASSETTES

AVAILABLE #C-15-52.50 ea

.1.7,........:.i_,,,---... I, CAS-6

-:-'.-1 "..a-1 $14.95

l (Case and 6 Cassettes)

SUP 'R' MOD II UHF Channel 33 TV Interface Unit Kit

rNde Band B/W or Color System * Convects TV to Video Display rot home computers, CCTV camera, Apple II, works with Cromeco Daz- zler, SOL -20, IRS -80, Challenger, etc.

* MOD II is pretuned to Channel 33 (UHF). Includes coaxial cable and antenna transformer.

$29.95 Kit

47

MOD II

AC Wall Transformer

..,.sP.m di;"^ .19r

Part No. Input AC 250 117V/60Hz AC 500 117V/60Hz

Ideal for use with clocks, power supplies or any other type of AC application.

Output 12 VAC 250mA 12 VAC 500mA

Price S3.95 S4.95

:«PBECISION

Model 2800 $99.95

Comes wrn lads mi rvi o manuai

a own'.

31,5 -Digit Portable DMM Powiee

3mon LED Dsplar Rarefy or se nneraton Auto ammo Ill/ Ill 01 ono tesolunpn

0ve'anve reading 10 meq inovo vneendnvt DC Acwracy 1'. arms?

Ranges: DC vorrage -01000V AC vana5e 0 1000V

Freq Response 50 400 HI DC AC Current S'rnOnA Resistance 0.10 map ono Ste 64 .44 .2 Accessories:

AC Adapter BC -28 59.00 Rechargeable

Batteries BP -26 20.00 Carrying Case LC -28 7,50

100 MHz 8 -Digit

2010100 woo norm Counter 6' LEO Display . Four parser sauces. r a

Crystal-caMrollea', nee.. carves. 110 or 220V with run. Automatic charger (2V with auto POnage - Cemponiy Slate ¡deter ano external selltantalned 7 2.1'1V Dower NON '15'6-- 1 75-.7M

MAX -10015134.95

)9.1238()0

ACCESSORIES FOR MAX 100: Mobile Charger Ellm(nalm use power from car oaarry Meant too - CIA 53.95 Charger/Ellminalor use 110 0 AC Model 100 - CAI 09.95

REMOTE CONTROL TRANSMITTER & RECEIVER

® - 519.9

15,C Mini -Max 6 Digit 50MHz Frequency Counter -- - Guaranteed frequency range of 100 Hz to 50 MHz

Pull 6 digit display with antiglare window Fully automatic -range, aplenty, slope, trigger, Input level switching not required. Lead -zero blanking -All to the loft of the first non -zero digit are planked. Kilo Mertz and Mega Hertz decimal points automatically light up when the unit 6 turned on. Built In Input overvoltage protection. Use 9V Battery or 110220V Dower. Complete with mini antenna. Lightweight - Only Boz.

INSTRUMENT/CLOCK CASE

This case is an injection molded unit that Is ideal for uSeS Such as DVM, COUNTER, or CLOCK cases. It has dimensions of 41,5"

in length by 4" in width by 1-9/16' in height. It comes complete with a red bezel.

PART NO: IN -CC $3.49 each

MINI -MAX $89.95

RS -232 CONTROL CENTER Plug in your modem, computer prom programmer, terminal, printer, etc. and selectively control data flow.

Same Contour as 'Pennywmstle 103 . Totally sell-conla,ned e Morales 2 maser Dons and 3 slave DO1S

PART NO. RS-232CC S89.95 kit only

Ideal for ate wtth the TRS 80 and others. "Plug/Jack intedace to any computer system requiring remote control of cassette functions".

The CCI00 controls cassette motor functions, monitors tape location with its internal speaker and requires no power. Eliminates the plugging and unplugging of cablesdur- ing computer loading opera. bon from cassette

`- 111141r9

i

CASSETTE CONTROLLER

e

/t"*

#Cc-1oD

S29.50

Accessories For Mini -Max Part No. Description MM -A4 Antenna MM -05 Carrying case MM-IPC Input cable with clip leads MM.512 11017 adapter MM-AC3 220V adapter

Price 5 3.95

5.95 3.95 9.95 9.95

S10.00 Minimum Order - U.S. Funds Only Spec Sheets - 25d

California Residents - Add 6% Sales Tax 1979 Catalog Available -Send 41C stamp

, ¡-.-,/tai

Nas, arneco ELECTRONICS

PHONE ORDERS

VPELCOME (415) 592.8097

MAIL ORDER ELECTROAYCS - WORLDWIDE 1021 HOWARD AVENUE, SAN CARLOS, CA 94070

ADVERTISED PRICES GOOD THRU APREL

63 -Key Unencoded Keyboard - v

1f1.-.-iG oiaM*wp1^ -e0 nt .. ... '

il-mr~iord This is a 63 -key, terminal keyboard newly manufactured by a

large computer manufacturer. It is unencoded with SPST keys, unattached to any kind of PC board. A very solid molded plastic 13 x 4" base suits most application. IN STOCK 529.95/each

Hexadecimal Unencoded

Keypad 19 -key pad includes 1-10 keys. ABCDEF and 2 optional keys and a

shift key. $10.95/each



5974009 514740114

5474024 5474034 5974049 5N/405N 5474064 5474074 54140811 5N7409N

5474106 5474114

51471124 5474134 514741414

5474164 SN741)N 54742014 5614214 5474214 5474234 5474254 5474764 5471274 91742914 5474304 5474324 5474374 54743814 5474394 6104404 5474414

7400 TTL S47470N 29 64747114 29

16 S47413N 35 .18 S471749 .15

18 5N7175N /9 18 SN74164 .35 ie S47479N 5.00

.20 S674804 50

.29 541483N .99

.29 51471834 .59

20 547.1854 .79 .20 54748614 35

59 5474694 1.75

.25 5474904 AS

25 54719114 .59

40 5874925 .43

70 5471934 43

.25 5474944 .65

25 5474954 65 20 5N74966 65

,39 5474974 3 00

.39 54741004 99

25 59741014 35

29 5N741094 .59 29 5471116N 1 95

.25 54741215 35 39 54741234 39

20 54741276 .49 25 56741256 49 25 5147412641 74126N 9

25 511741324 75

25 56741364 75

80 66141419 79

89 59741432, 2 95

51474/214 49 54741436 1 95

5474934 75 54741449 2.95 54744114 75 514141454 .79 5474454 75 56741474 1 95

51474494 69 514741484 1 29 5474479 59 59741504 59 5474184 79 54741514 .59

5674504 .20 54741534 59

51474514 20 56741539 59

51474536 20 54741514 99

5474544 20 54141556 19

59/4594 25 567/1564 19

$4I4604 20 S6711574 65

54741604 89

S474161N 89

54741624 1 95 547416314 .89 S4741644 89

54741654 89

5N741666 1 25

56741674 1 95

5N741704 1 59

51174172N 6 00

S9741739 1 25

5N74174N .89

54741754 79

54741764 79

SN711774 79

54711796 195 54741804 79

614741814 1 95

54741824 79

54741844 195 S414185N 1 95

514741864 9 95 54711886 3 95

514741906 I 25

S474191N 1 25

56741924 79

514741934 79

5N7419/N 89

5N74195N 69

514741964 89

54741974 89 56741984 1 49

5474199N I 49

SN74S200 4 95

54742514 1 79

S474279N 79

W42&34 2 25

S1174284N 3 95

514742854 3 95

5N743654 69

S47.1366N .69 547436714 69

5674368N 69 514743904 195 SN143931r 1 95

20% Olscount 100 pre combined order 25% -1000 pcs cOmbined order

JELECTRONICS

Regulated Power Supply

ameco Kits 4 -Digit Clock Kit

Uses lM 309K Herd sink pevrdec P.C. board construction

Pr ion a solid 1 amp P 5V Includes components, hardware

and Instructions Sue: 3.1/2" 6 5" a 2" high

JE200 5v lamp *14.95 ALSO AVAILABLE:

JE900 - Digital Stopwatch kit $39.95 JE22066 Function Generator $19.95

JE701 - 6 Digit Clock kit $19.95 JE747 Jumbo 6 d'git Clock kit $29.95

V Bright .357" ht red áí8íh0

Sequential 911951ng colon 12 or 24 hour operation Extruded alum case m (black) Pressure switches 700 haws, minulls and hold 1u0 s

Includes an components. use and wan Mansiormeru" Sur 3.1/4" 4 13/4" 0 1.1/4"

JE730 *14.95

DISCRETE LEDS .200 Ola.

XC556R red 5/51 125" Iles. XC556G green 4751 XC209R red 5/51 5C5560 yellow 441 XC209G Oreen 4/51 XC556C clear 4/S1 XC209Y yellow 4/51

.200 tila. .185' dla. XC22R red 541

XC526R red 5/51 XC22G preen 4751

%052áG green 4/51 %0220 yellow //St

8C5260 yellow 4/31 .170' 8la. XC526C clear 441

880700 red 441 .190" Ola.

XC111R red 5/51 )(CMG XC111Y yellow 4%51

XC111C Clear 4/51

.085' die. MV50 red 6/S1

INFRA -RED LED 1/4'91/4'91/16' Ilal

541

TIMEX T1001 LIQUID CRYSTAL DISPLAY

FIELO EFFECT r 22a lilllllll ÍIÍlllrlé 4 04025 - .5" CHARACTERS

THREE ENUNCIATORS 2.00.41.20"PACKAGE INCLUDES CONNECTOR

T 1001.Transmissive 57.95 T 1001AReflective 8.25

C04000 CD4001 C04002 C04006 C01097 CD4009 004070 CD4011 CD101] C04013 C04014 C04015 CD4016 CD40t7 CD4018 004019 CD4020 C04021

C04022 CD4023

004024 C04025 CD4026

C04027

; C/MOS 23 004026 99

119 CD4029 1 19

25 004030 49 C04035 99

49 C04040 1 19

23 004041 125 25 C04042 99

39 001043 B9

139 004044 89

1 19 CD4046 1.19 49 CD4047 2 50

119 CD4048 1.35

.99 C01049 .49

.49 C04050 49 119 C04051 1.19 1.39 004053 119 1.19 C04056 2 95

23 C04059 9 95 19 004060 1.49 23 CD4066 79

2 25 CD1068 39

69 004069 45

004070 004071 C01072 C04076

49 CO4087 C04082 004093 C0a098 MC14409 61014410

1.1014411

NCI 4119 NIC14431

MC14506 MC14507 MC14562

MC11583

C04508

C04510 C04511 C04515 C04618 004520 CD4566

55

23 49

139 23

23 99

2 49

14.95 14.95 14 95

4.95 19.95

75

99

14 50

3 50

3 95 1.39 1 29

2 95 1 29

29

2 25

74000 74002 74004 74008 74C10 74C14 74C20 74030 74042 74C48 74073 70074

.39

.39

.39

.49

39

1.95 39

39

1.95

2.49 .89 89

74C00 74C85 74090 74093

74095 740707

740151

740154

740157

740160 140161

2 49

1.95 1.95

1.95 125 2.90 3.00 2 15

2 49

2 49

740163 740164 740173 740192 740193 740195 740922 740923 74C925 740925 90095 80097

2 49

2 49 2.60 2.49 2 49

2.19 5,95

6.25 9.95 8.95 1.50 1 50

79/AG 1.75

LM106H .99

LM300H .80

LM30ICN/11 .35

1M302H 75

0M30411 1.00 LM305H .60 LM307C6M .35

LM308CN/11 1.00

083094 1.10 193096 1 25

L1410CN 1.15

IA1311MM 90

1.143121.1 1.95

1.1.13176 6.50 11431804M 1.50

1143194 130 163206.5 1 35 LM32011.5.2 1 35

193206-12 1.35 193206.15 1,35 L143206.18 1.35 LM320624 1.35 063207-5 1 25

1643207.5.2 1.25 11.13207-8 1.25

1M320T-12 1.2$ L93207-15 1 25

1M3207 -I13 1.25

1143207-24 1.25 193236.5 5.95 193246 1.80

LM339N 99

193406.5 1.35

183406.6 1.35

093406.8 1 35

193106.12 I 35 11.13806-15 135

LINEAR LM71N .39

1843400-18 1.35 11.11239/11 .55

1113406.74 1.35 11.17335 100

1613407-5 1.25 1.1.17396 1 19

1113401-6 1.25 LM741CN/11 .35

193401.6 1.25 114741-149 .39

183401.12 1 25 1974714/4 .79

LM3401-15 1 25 LM718N/H 39

153407.18 1 25 14113104 2.95 193401-24 I 25 1414567674 59 1M3584 1 00 9C1488N 1 39

11.437014 1.95 64014696 1 39

093135 3.25 L0149614 .95

11.43775 4.00 0915564 1.75

193800 1.25 9C1711507 3.00 1.1138004 .99 11,121116 1 95

16839114 1.79 1929019 2 95 15138227 1.19 1143053N 1 50

9E5014 8 00 1930654 1 49

645104 6.00 19090014(3401).49 14E5294 4 95 141390514 .B9

4E5311107 3.95 11439099 1.25

9E5361 6.00 61055580 .59

NE5401 6.00 80380 4.95

NE5444 4 95 L51754504 .49 9E5504 1.30 7545106 39 4E5550 .39 75452CN 39 NE556N .99 75453CN .39 5E56011 5.00 754540N .39

NE5618 500 7549109 79

9E5628 5.00 7549204 .89 4E565400 1.25 754934 .89 9E56609 1.75 75494410 .89

9E567V0I .99 604116 1.25 NE5704 4.95 5C4151 2.85 1M703C6111 .69 RC4194 595 11/17099711 .29 60/195 4.49

TYPE

MAN I

MAN 2

MAN3 MAN4 MAN 76 MAN 7Y

MAN 72

8449 74

MAN 02 MAN 84 MAN 3620 MAN 3630

MAN 3640

MAN 4610 4466 4640

MAN 4710

MAN 1730

MAN 4740

MAN 4810 MAN 4840

MAN 6610

MAN 6630

MAN 6640

MAN 6650 MAN 6660 MAN 6680

MAN 6710

DISPLAY LEDS POLARITY NT PRICE TYPE PO051Ty NT

Common Anode -red 170 5 4 7 Dol Mamx.red 300

Common Cathode -red '25 Common Cathode.. '87 Common Anode9reen .100

Common Anode.yellow 100

Common Anode -red .100

Common Cathode -red .100

Common Anode,yellow .780

Common Catno0e.ye0ow .300

Common Anode orange .103

Common Andde.oranpe m 300.

Common Cahode-orange .300 Common Anode -orange .100

Common Canode-orange .400

Common Anode -led .400

Common Ano0e.re0 0 I .400

Common Calno0ered 100

Common An0de,yennw 400

Common Calnode.yellow .100

Common Anode -orange -D D .560 Common Anode -orange T 1 .560

Common Camodo-nun9e.O.13. 560

Common Cainodeorange o 1 .560 Common Anode -orange .560 Common Cathode -orange 560 Common Anode -red -D.0. 560

PRICE

2.95 MAN 6730 Common 679400-1e0 e I 560 99

4.95 MAN 6740 Common Cainw8.red-0.D. 560 .99

25 MAN 6750 Common Calnode-red 4: 1 .560 .99 1.95 MAN 6160 Common A,Ode-red 560 .99

1.25 MAN 6780 Common Canodered 560 .99

99 01701 Common Arodl.red a I 300 .99

99 01.701 Common Canode-red .300 .99

1.25 01107 Common 4m48.,e4 .300 99

.99 01726 Common Canode-re4 .500 1.49

.95 01741 Common 90090.200 600 1.25

.99 01716 Common Anode -redo I .630 1.49

99 01747 Common An00ere0 .600 1 49

.99 01719 Common 007006red n I .630 119

.99 01150 Common Cathode.Ted .600 1 49

.99 01339 Common 0011001 ,00 .110 .35

.99 1N070 Common Canode 250 .69

.99 FND358 Common CAh90e 0 I .357 .99

.99 790359 Common Canode 357 .75

.99 090503 Common Calnode/FND500I 500 .99

.99 FND507 Common Anode (190510) 500 99

.99 5082.7730 Common 07040 ,60 .300 1 30

.99 HDSP-3100 Common Anode.red .800 2.10

.99 HOSP.3403 Common Canode red .800 2.10

.99 5082-1300 4 a 7 sal 0g4'RH0P .600 19.95

.99 5082.7302 1 x 7 591. CIOd-LMDP .600 19.95

.99 5082-7304 Overra098 maracIe1 (-I) 500. 15.00

.99 5082.7340 4 x 7 Sol. Digit,HeuOeomal .600 22 50

RCA LINEAR CA30131 2.15 C0308214 2 00

CA20237 2.56 CA3093N I 60

CA3035T 2.48 C030866 85

C030391 135 C530899 3 75

C4304614 1 30 CA31301 1 39

CA30599 3.25 0431/01 1 25 C4306011 3.25 0031601 1 25

CA30807 .85 CA31019 49

GA308111 2.00 0036009 3 50

CALCULATOR CHIPS/DRIVERS

965725 955738 590864 0518865 0118887 0788809 93`1 7 sec

CO. LED driver

52.05 2.95 2 00 1 00

75 .75

CLOCK CHIPS

895309 54 95 MM5311 4 95

147.1531295 695314 4 95

965316 6 95 #95318 9.95 005359 2.95 MA15387/19984 4 95 065841 9 95

MOTOROLA 140140817 51.95 MC140818 5.75

141C1439L 2.95 MC3022P 2.95

MC3061P 3.50 8C4016(74416) 7.50 MC4024P 3.95 MC4aoP 95

MC4044P 4.50

AY -5.9100 603-9200 AV -5-9500

TELEPHONE/KEYBOARD CHIPS Push Button Telephone Dialler Repertory Dialler CMOS Clock Generator

AY -5-2376 Keyboard Encoder 900155 Keyboard Encoder 16 keys 74C922 Keyboard Encoder 16 keys

ICM CHIPS CMOS Precision Timer CMOS LED SIopwatch/l9mer Osdllator Controller Seven Decade Counter Clock Generator

ICM7015 ICM7205 ICM7207 ICM7208 ICM7209

514.95 14.95 4.95

14.95 7.95 5.95

24.95 19.95 7.50 19.95 6.95

MCM6571 MCM6574 MCM6575

NMOS READ ONLY MEMORIES 128 X 9 X 7 ASCII Shined with Greek 128 X 9 X 7 Math Symbol 8 Pictures 128 X 9 X 7 Alphanumenc Control Character Generator

13.50 13.50 13.50

T1074CN 11.494CN TL496CP 11C90 951490 4533 MK50240 DS0026CH TIL308 MM5320 MM5330 10110/111

MISCELLANEOUS Quad Low Noise bi.fet Op Amp 2.49 Switching Regulator 4.49

Single Switching Regulator 1.75 Divide 10/11 P180041e1 19.95 HI -Speed Diode 10/11 P005041er 11.95 Photo-Darington Opto -Isolator 3.95 Top Octave Freq. Generator 17.50 5Mhz 2 -phase MSS clock dnver 3.75 .2r red num. display w/Inleo. logic chip 10.50 N Camera Sync. Generator 14.95 407 Digit DPM Logic Black 5.95 39e Digit A D Converter Set 25.00/set

LITRONIX ISO -LIT 1

Photo Transistor Opto-Isoator (Same as MCI 2 or 4925)

2/99¢

SN 76477 SOUND GENERATOR

Generates Complex Sounds Low Power Programmable

3.95 each TV GAME CHIP ANO CRYSTAL AY -3-8500.1 and 2.01 MHZ Crys al (Chip & Crystal

includes scare display. 6 games and select angles. ett. I .9 5/S e XR205 58.40 XR210 4.40 X9215 4.40 XR320 1.55 XR-L555 1.50 99555 .39 XR556 .99 XR567CP .99 XR567CT 1.25 XR731OP 1.30 XR1468CN 3.85 X61488 1.39 091469 1.39

TYPE

16746 14751 16752 14753 14754

14757 14759

114959

14965 145272 1145234

145235 145236 145242 145215 16456 114458

1114854

144001

DIODES 170115 W

33 40pm

5.1 ddlm 56 400m

6.2 400m

6.8 400m

90 amm 12.0 400m 82 400m

15 100m

5.6 500m 6.2 5000 6.8 500m 7.5 5000

12 500m 15 5000 25 40m

150 70 180 10m

50 PIV I AMP

EXAR JE2206KA 14.95 JE2206108 19.95 X91800 3.20 X92206 4.40 892207 3.85 592208 5.20 392209 1.75 592211 5.25 X62212 4.35 XR2240 3.45

PRICE

4/1 00

4E1 00 4/1 00 1/1.00 4/1.00 1/1.00 1/1 Do

4/2.00 4/1.00

28

28

28

28

ze 28

6/1 00

6/1 00

5/1 0D

12/1 00

TYPE

144001 144003 164004 144005 144006 144057 143600 164148 194154 144305 144734 141135

191736 144738 144742

144744 141183

141184 192185 161186 1141188

XR2242CP X92264 XR2556 X92567 XR3403 5R4136 X94151 XR4194 XR4202 094212 XR4558 X94739 594741

VOLTS W

100 710 1 AMP

200 PIV I AMP

400 P19 1 AMP

600 Ply 1 AMP

BOO PIV 1 AMP

1000 715 1 AMP

50 200m 75 100 35 IOm

75 25m 5.6 Iw 6.2 I. 6.8 Iv/ 8.2 lR

12 Iw

15 I 50Iv/ P1035 AMP

100 715 35 AMP

150 710 35 AMP

200 1310 35 AMP

400 P7005 AMP

1.50 4.25 3.20 1.99 1.25 1.25 2.85 4.95 3.60 2.05

.75 1.15 1.47

PRICE

1211 00 12/1 0) 12/1 00 loll 00 1011 00 10 100 6100

15 100 12100 IS 1 00

28

28

28

28

28 28

I SO

110 1 70

1 80

300

SCR AND FW BRIDGE RECTIFIERS 0360 150 04 4000 SCR12418491 51.95

G4861 354 W 600V SCR 1.95

242328 1.6A Or 3000 SCR .50

900 980.1 12A or 50v FW BRIDGE REC. 1 95

MCA 9603 174 A. 2000 126 BRIDGE REC 1 95

6 Dm LP

14 pm LP

16 pin LP

18 pn LP

20 pin LP

14 pin 5T

16 píh51 18 pin ST 21 pin ST

IC SOLDERTAIL - LOW PROFILE (TIN) SOCKETS 1.24 25-49

517 16

20 .19

0 21

29 .28 34 .32

1.27 .30 35

.49

.25

.27

.32 .15

8 pin 50 5 30 .27 14 pin SG .35 .32 16 pm SG .38 .35 18 pin SG .52 .47

8 pin WW 5 39 38

10 O.n WW .45 .41 1413 WW .39 38

16 pm WIN .43 .42 18 Don WW x75 66

50100 1/ .15 22 pin 3 5 .37

.18 24 pin 1P .38

.20 28 is. ,P .45

27 36 pin EP .60

.5D SOLDERTAIL STANDARD (TIN) 20 w" LP .63

21

.25

.30

A2

.24 .29

32 .43

.31

.37 37

A1 62

2e yin ST 5 .99 36 pm ST 1.39

0 p9 ST 1,59

SOLDERTAIL STANDARD (GOLD)

NM AIM 24 pin 50 s .70

28 pin 5G 1.10

36 ph SG 1.55

40 pin SG 135

WIRE WRAP SOCKETS

(GOLD) LEVEL .3 - 22 on WW 5 .95 24 Din WW 1.05 28 pin WW 1.40 36 011 MN 1,59 40 pin WW 1.75

25.19 51100 .36

.37 .35 .36 .43

.59 .58

.62 Al.

.90 1.26

1.45

.81

1.15 1 30

63 .57 1.00 .90 1.40 8.26 1.59 1.45

.85 95

1.25 165 1.55

.75 ,8S

1.10 1.30 1.40

C10681 1475405 975006 11597

5598 40109 40110 40613 26918 2622194 2622210 2622224 P92222 Plastic

262369 2623694 51752359

262484 242906 242907 71129217 Plastic

262925 M1E2955

263053

so TRANSISTORS 293901 30 263055 .09 2143905

5/1.00 1.1JE3055 100 263906 611.00 243392 5/1 00 261093 6/1.00 283396 5/1 00 244123

1.75 PN3567 311 00 764249 1.75 743568 4/1 00 744250 1.75 743569 411 00 244400

4/1 00 417536388 5/1 00 244401 2/1 00 MP53702 5/1.00 264402 4/1.00 243101 5/1.00 264401 5/1 00 M753704 5/1 00 244409 7/I 00 2143705 5/1 00 295066 511 00 M753705 5/1 00 245087 411.00 243706 5/1 00 245088 5/1.00 1/1053706 5/1 00 2450119 411.00 243707 5/1 00 245129 4/1 00 243711 5/1.00 1145134

511 00 2937244 65 765136 7/1,00 2437254 100 245139 5/1.00 263772 2 25 2115210-

1.15 263823 1.00 295149 211 00 253903 5/1 00 265951

4/1 00 4/1 00 4/1 00

3/1 00 611 00 411 00

4/1 0D

4/1.00 411 00

4/1 00

4/1 00

5/1 00

4/1 00

4/1 00

4/1 DO

4/1 00

5/1 00

5/1 00

511 00

5H 00

5/1 00

3/1 00

311 00

711600 .23 741501 23 74LSDOTTL iil55iiº 741502 .23 711541 69 7416151

741503 23 740551 23 7415155

741504 .29 741554 .23 7415157

741505 29 741555 .23 7415160

78L508 23 74E573 .35 741.5161

741S09 .29 741574 .35 7415162

741.510 .23 741515 .49 7115163

741.511 .60 741676 .35 741.5164

74313 49 7<1578 39 7415175

741514 .99 741583 .75 7115181

741515 .29 741585 .99 7415190

741520 .23 741586 .35 7415191

741521 29 741690 A9 7415192

741522 29 741992 .59 7115193

741526 .29 74L593 .59 7415194

711527 .29 741595 .19 7415195

741520 .29 741596 .89 7115253

701530 .23 7415107 .35 7415257

711532 .29 1415109 .35 1415258

741537 .35 7415112 .35 7415260

7<1540 .29 7415123 .99 1415279

741542 69 7415125 .69 7415367

1415132 .19 7415368

7415136 39 7<15670

.69

.69

.69

.69

.69

.89

89

.B9

95

]9 2.49

.89

89 09

89

89

.59

.19 69

1.39

55

.59 59 59

1.95

1/4 WATT RESISTOR ASSORTMENTS -5% ASST. 1 5 ea

ASST. 2

ASST. 3 5 ea 6.70

ASST.4 5ea

225

ASST. 5 5 ea 566

1506

ASST. 6 5 ea. 3904

ASST. 7

ASST. 8R

10 01491 12 867/ 15 01111

27 02161 .4.' OHM 39 0717.7

68 OHM 820076 700 OHM

5ea 180001 220 OHM 2100140

475 009 566 00467 680 OHM

1.86

3.34 9,30 476 8.20 176

336

670

Irá

7.6 614

78 OMM 22 008 47 OHM 56 OHM

170 091M 150 0061

3300080 390 OHM

870 0,1 12

2 26 7.7s

5.66 5.82

154 186

396 414

7000. 770ía

1819 7706 7202 1306

451 9604 5806 1796

114 1.758 158 6.85 2.752

5 ea. 2.7M 3.346 3.9M 4 )M 5.6M 50 PCS 1.75

Includes Resistor Assortments 1.7 (350 PCS.) $9.95 ea.

50 PCS

50 PCS

SO PCS

50 PCS

50 PCS

50 PCS

S1.75

1.75

1.75

1.75

1.75

1.75

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510.00 Minimum Order - U.S. Funds Only Spec Sheets - 25l California Residents - Add 6% Sales Tax 1979 Catalog Available -Send 410 stamp

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12 10 .07 02201 13 .11 .08

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020% GIPPED TANTALUMS 1601101 CAPACITORS 28 .23 .17 1.57350 30 .26 21

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.28 23 .17 15/250 63 50 A0 MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS

Axial Lead 1401.1 lud 15 .13 I0 .871259 .15 13 .10 16 .14 .11 47/506 16 14 II 14 .12 09 1.0/165 15 .13 10

15 13 10 10/250 16 Ia .11

15 .13 .10 10/505 16 14 11

.16 14 12 4 77165 15 13 10

.17 .15 .12 4 725V .15 .13 .10 24 20 .18 4 77500 16 14 11

19 17 15 101160 .14 .12 09 25 21 .19 101255 .15 .13 .10

.24 .20 .18 10/500 16 .14 12

.15 30 1) 477505 14 .21 .19

32 24 25 100/160 .19 .15 .14 45 41 38 100259 21 .20 .18

33 29 .27 100/579 35 30 28

55 50 A5 2201160 23 17 16 70 .52 .55 470/250 31 28 26

m r m n 33

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APRIL 1979 99


REGULATED POWER SUPPLIES

POWER SYSTEMS N PS1111 115-230V 50/60 cy. In 5v DC at 35A out, 6"x 16'4"x 150" 26 lbs. shippIng weight 585.00 POWER SYSTEMS lY PS1106

p 115-230V 50/60 Cy. in 12v DC at 15A out. 5110 1614"x 5" 19 lbs. shipping weight. 575.00

(0v PROTECT/

C/MOS IDIODE CLAMPED) 4001 - 18 4019 - ,37 4050 - .35 74C74- 45

i; 4002 - .18 4020 - 4006 - .95 4021 - 4007 - .18 4022

p 4009 - .77 4023 - ', 4010 - .37 4024 - 1 4011 - 18 4025 - " 4017 - .18 4027 - ` 4013 - .29 4028 -

4014 - 75 4029 - 4016 - .75 4030 - 4016 - 29 4035 - 017 1.05 4042 -

- 4018 90 4049 - 14. 5]7 INTERFACE -

nEE n,si.s.AV : - 76132NAFIAG GEN.

aEc - 1. 8263 - 1 95

2700.88 EIRD0 1450 AO 75

eDs0YN.6 311Ss ..51013 T_5.25 3716 PI - 3595 mr028V

1103.1 (ASO 70]6 TELEDYNE 6 BIT AD 4 1 CONVERt_ 9.95 OYN. - 34s vi 1.25 rsAT- 0.95

7.75 Us 8010 0-

° ºnr-256.STATIC- >rs .216 0 25

90 4053 - 1.10 74C83- .90 4055 - 1.25 74C86 .00 4066 - .70 74C9]- .18 4069 - 45 74C151 .75 4071 - IB 7aC160 18 4072 - .21 74

'PRINTED CIRCUIT BOARD 4-1/7"6-1/2" 51561.E SIDED EPDXY BOARD 1/16" thick unelehed 6.60 ea. 5/52.60

7 WATTLD-65 LASER DÍODE 1R S&95 2N3820PFET 5 45 25 6457 N FET 5 45 252646 MT 5 45 ER 900 TRIGGER DIODES 4 SI 00 2N 6028 PROG UJT 565 MINIATURE MULTI -TURN TRIM POTS 100, 1K. 2K, 51, 10K. 20K, 50K,

1 15 200K. 1Meg, 2Meg. 5.75 each 3/52.00 40 75 CHARGED COUPLE DEVICES

140 CCD 201C 100x 100 Image Sensor 595.00 1 05 CCD 202C 1000100 Image Sensor 5145.00

CRYSTALS 53.45 ea 4 U00 M11e

6000611, 000 BOO

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C 161 1.05 31 40]6 - 97 7401]4 00 1,05

VERIPAX PC BOARD a

epoxy 80 4516 - .95 This board Is a 1/16 -single sided paper 50.00 17520 70 740175 1 OS board. 4vs"x6 M" DRILLED and ETCHED which .95 74000- .22 740197 1.20 winhold up to 21 single 14 pin IC's .r 8,16 or LSI 33 74002- ,22 740193 170 DIP IC's with busses for power su PPly Conn.t.r. .97 74008 22 74C901 á8 FP 100 PHOTO TRANS S .50 ,65 74010- 77 740003 8 .

.35 74073- 65174C914 170 RED, YELLOW, GREEN, or AMBER LARGE LED's. 2" 6!51.00

xsTAT 11414TIL-118 OPTO -ISOLATOR 5.75 11 se M C T.6 O PT O ISOLATOR .. 5 .80

1.35 521001070 48 YNAAN-

1 WATT ZENERS: 3.3 4.7 5.1, 5.6, 9.1, 145 30503 - 720 5%4. °RoM - 10. 12, 15, 18, or 22V 6/S1.00

MCM 6571 A 7 x 9 character gen $ 10.75

8130 - 2.95 8834 - 2.25 8131 - 2.95 8837 - 2.25 87380 - 2.25 8838 - 2,25 8830 - 2.95

Silicon Power Rectifiers PRV IA 3A 17A 501, 1756 140A 100 06 14 30 80 1 1 5 00 200 07 70 35 1 15 4 75 6 50

RIBBON CABLE 400 09 25 50 I 40 650 9.50 r LAT (COLOR COOED/ 600 11 30 70 1.80 850 12.50 Mao WIRE Ph IS 35 90 230 10.50 16.50

1000 20 45 1 10 ? 75 12.50 20.00 SAD 1024 a RE OICON 1024 stage analog 'Booker Brigade" sn.11 re0lslr 014,95

40 00,10, -.75/per fool 50 <o.ld. .90/per tool

CTS 2068 ei,h1 posdlon dip sw.len .... S 1.60 C ,5.2064 foul 001110, 3,8 switch ..,,S1.45 LIGHT ACTIVATED SCRs TO 18. 700V IA S .70

SILICON SOLAR CELLS 20" diameter .4V al 500 ma 54.00

FND 359 C.C..4" 5.60 LED READOUTS '

PCS 8024 4 mg11 131.-704 C.A. ,3" $ .75 C.C. 8" display 55.95 DL 747 C.A 6" $1.25 END 503 C.C. .5" 5 .85 HP3400 .8"CC 01.95 END 510 C.A. 5" 5 .85 HP3405.8"CA 01.95 DL -104..3" C.C. S .85

Timis: FOB Cambridge, Mess. Send Cheek or Money Order. Include Postage, Minimum Order $5.00, C- '$ 520.00

15 4148 115914

RS232 CONNECTORS

123K5V 3A 3091( 723 3207 -

5, 12, 15 or 24.

'Send 25! foeoor catalog featuring Transistors and Rectifiers

145 Hampshire St., Cambridge, Mass.

15(S1,Oa

DB 25P male DB 25S female. HOODS

REGULATORS .55.75 34K-12,15 $ 1.10 or 24 V . . . . $ 1,10

5 .50 340T - 5, 6, 8, 12 15,18or24V91.10

78MG S1.35 .$1.10 79MG 51.35

62.75 °

02.95 5/ 00

TRANSISTOR SPECIALS 2N6233.NPN SWITCHING POWER 51.95 MR F.8004 a C8 RF Transistor NPN 5 .75 253772 NPN Si TO -3 . . . . . S 1.00 251546 PNP GE 70.3 S .75 254908 PNP S, TO 3 5 1 00 255086 PNP 5, 70,92 . . . 4'5 1.00 2.3137 NPN SI RE 5 .55

253919NP5S,TO3RF S 1 50 º

2N1420 NPN Si TO 5 3/5 1.00 253767 NPN 5, TO 66 S 70

252222 NPN S. 10,18 5 S 1 00 253055 NPN 5, TO 3 . . S .50 253904 NPN S. T097 6/5 1.00 753906 PNP 5, T097 . 6/5 1.00 e

255296 NPN S. TO 220 . . . S 50 1

256109 PNP S. 70-220 . 5 .55 51636 PNP 5, TO 5 . . . 5/S 1 00

MPSA 13 NP Si 4/5 1.00

TTL IC SERIES 34'6

7403 - 15

7404 - 18

t 7407 - 7408 -

MO 10

it 7412 7413

8116

7470

74.

.n 1430

7438 81.40

7441

7447 7445

60

22

n

45

65

74122

74.

7.3 7417 7.0 7471,

7407 7.3

441.5

7.1 1497 7493 MAI 7495 7496

74107 74121

/4125 74126

741. 74150

30 21

1.15

.58

43 57

65 .90 28

40

40 4s

110

01

00

7415.1

74154 04

74157 - 55 7415.11- 65

e7- o 74163- 55 74164.. a6

74170- 1 5/I

74174 95

74177 - 75

a5 14191 - , 90 74190- - 74151- 85 M192 - 79

74193- .79

74195 - 50

º6- BS

74197 - M7T9- .Y

.90

M393- 325 74375- 1.50

DATA CASSETTES 1/2 HR S 95

14 pin headers 3/01,00

MM 5387AA new clock chip Which will 4,rectly drive LED's 12/24 hrs., 1 supply & alarm 05.95

NO d WIRE WRAP WIRE SINGLE STRAND 100' 01.40

ALGO I IATURE TOGGLE SWITCHES MTA 106 SPOT . 5 .95 MTA 206 DPDT MTA 206 P.OPDT CENTER OFF 5 1,85 MSD 206 P.DPDT CENTER OFF LEVER SWITCH, , .. .

5 1.85

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PRV 100 200 400 coo

Full Wave Bridges' DIP SOCKETS B PIN .17 24 PIN .35

14 PIN .20 28 PIN 40 , 16 PIN ,22 40 PIN 60 , 18 PIN 25

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743570

7435281 " 743530

xS:n

7415109 /4.317 /435113 1445114 74.124 7435125

, ti' a

PR V

o 100 200 400 600

SANK EN AUDIO POWER AMPS Si 1010GI0 WATTS..., 5 7.80 S, 10 70 WATTS $15.70 5, 1050 t4 50 WATTS . 528.50

TANTULUM CAPACITORS .22UF 35V 5/91.00 .47UF 35V 5/01.00 .68UF 35V 5/01.00 lUF 35V 5/51.00 2.2UF 20V 5/51.00 3.1UF 20V 4/$1.00 4.7UF 15V 5/$1.00

743502 31

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6.BUF 35V 4/01.00 IOUF 10V 5.25 22UF 25V $.40 15UF 35V 3/01.00 30UF 6V 5/51.00 33UF 20V $,40 47UF 20V 0.35 68UF 15V 5.50 °

_IiPi..CIRCUITS M 101 75

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97

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1.

337 119

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co 3011748 LM307 LM 306 las

M 311 ne

M 324 M 339 M 358

LM 370 L. 3)3

LM 380 LM 382 LM388 LM 187 CO 533

553 LM 555 LM 556 NE540L 560 565

567 703

71111 5923 709 0

1C o, V

747 M 1]10

1456

0900

BO38CC 791

LE 35614

TRIACS SCR'S IA 40 70

1.10 1,70

10A 25A 70 1 30

I10 1 75 1 60 2 60 2.30 360

26 .30 75

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0 .' 0

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95 1.25 .80 I25 2.50 2 50

39 .85

2.25 2.00

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M. 90 75 95 25 .35 25

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20

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WE SHIP OVER 95% OF OUR ORDERS THE

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am U1TEETED ELEETFD1h[Ei

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SN76477 Complex Sound Generator $3.50 This is a programmable sound effect generator capable of producing a wide variety of sounds from high to low frequency. Using this chip & a small number of inexpensive parts, a variety of projects may be built. Spec shs & application notes $1 .00

TL500 Analog Processor $8.50 The TL500 contains all the active analog elements for an automatic zeroing and automatic polarity- It is a 13 -bit dual -slope A/D converter that has true differential inputs. It requires 3 caps, & 2 resistors with no special matching or tolerances. It is designed for use with the TL502. Spec sheet $ .25

TL502 Digital Panel Meter L.D. $7.50 This is a 4% -digit Digital Panel Meter L.D. that is designed to interface with the TL500 analog processor. It provides base drive for external PNP digit & segment drivers providing direct interface with 7 -segment display. Spec sheet $ .25

LD130 A/D Converter $5.50 Single -reference voltage, auto zero and auto polarity. It is designed for Digital Voltmeters, Panel Meters, Digital Thermo- meters, Microprocessor Interfaces to Analog Signals, & General Instrumentation. 34-pg. Spec & Application notes $2.50

MM5865 Programmable Stopwatch $7.50 7 -function Universal Timer and Stopwatch. Start/stop with elapse time, start/stop accumulative event time, split, sequential total elapse time, rally total elapse time, program up and down count- It uses 32.8 KHz crystal or external clock. Spec sheet & 10 -page Application notes $ 1 .5 0

32.8 KHz Crystal $4.00

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1142 DATA CASSE11E110 min 1147 0500711. S W roll 5e00,,151.80 1324 SOUND ACTIVATED SW ITCN.es 1226 UNI CORDS, IB, 2 coed w/plug 1011 12uF TANTALUM 305 4..1 1013 1012 1luf TANTALUM ES5 0001 1007 1 TRANSFORMER 100ma, PC mown

1111 154145 SWITCHING DIODES lull bad 714112 TEXAS INST, TTL DATA BOOK 21102-2 M 250nsec 1102 RA 211035 .2 RAM JS 1291 3 POS ROCx1Rm 12 O SWITCH 1

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1100 3.00

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structions. Withmsullaom in

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2510 100 195

1156 IRS. 166 M11.10110 ADD-ON BIT 1199 115-237 PRINT I R INTERFACE 1415 37 READOUI,MAN 74 egu.1 INST4RI, 1117 14 PIN SOLDER TAIL SOCKETS 1117 lb PIN MIDI RTAII SOCKETS 1117 24 MN SOL5

RECTIFIER SOCX011115 S

1001 154001. 505 IA RECTIFIER 2010, 1.00 1018 S.11111471 TENER .. .. .. .. .. .. .. .. . 1010,1.00 .

1018 Dv WATT MIER 1018,1.00' 1034 75 AMP, 100 P15 -111OCR BRIDGE 150 1111 50LDERING IRON. penal! hphlOW 130 1020 470 63 updte l7 lot 1.00 1020 2301. 250Ink Y55,1.81

Mi 15 1167 40 CONO RIBBON CABLE per loot SO 1160 104 x11.7 pain' 3 weal port, 140 00 1087 PROM PROGRAMMER 1DRIVE,Irom DAE 227100 1154 SHUGART.MINIFLOPPY DRIVES/4450 37500 1011 S' RI A DOUI, 0G...501 .75

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"LIFT -IT" PC DUPLICATING KIT $25

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30 Oxk z ^d plr! No additional 36c h required NO camera

1093 SARGON CHESS,I 19,95 1041 STAR EREIL II 195 1016 SCITIGAMSSAMP911 VII 195

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1979 $45

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ORDER BY MAR, 011055. MASTERCHARGL VISA. CODS 06 1 ADD 0130 FOR POSTAGE 8 IIANDIING

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Mlnlmum order 55.00 US currency. Check or money order only. Add 5% to cover sN inping end handling charges. Calif. residents old 6% sales la.. Santa Clare County resident, add 6.5% sale, lau-



Nod: 1; PartstPIace.po -A

L w Prices . and_..New Items Y

Ever da y ! °

m o p y , t

Top-quality devices, fully functional, carefully inspected. Guaranteed to meet all spec-fications, both electrically and mechanically. All are made

by well-known American manufacturers, and all have to pass manufacturer's quality control procedures. These are not rejects, not fallouts, not

seconds. In fact, there are none better on the market! Always count on Radio Shack for the finest quality electronic parts!

TTL and CMOS Logic ICs

Full -Spec Devices Direct from Motorola and National Semiconductor

Type Cat. No. ONLY

7400 276-1801 350 7402 276.1811 39C 7404 276-1802 350 7406 276-1821 490 7410 276-1807 390 7413 276-1815 790 7420 276-1809 390 7427 276-1823 490 7432 276-1824 490 7441 276-1804 990 7447 276-1805 991 7448 276-1816 99C 7451 276-1825 390 7473 276-1803 491 7474 276-1818 490 7475 276-1806 790 7476 276-1813 590 7485 276-1826 1.19 7486 276-1827 490 7490 276-1808 790 7492 276-1819 69C 74123 276.1817 990 74145 276-1828 1.19 74150 276-1829 1.39 74154 276-1834 1.29 74192 276.1831 1.19 74193 276-1820 1.19 74194 276-1832 1.19 74196 276-1833 1.29 4001 276-2401 490 4011 276-2411 490 4012 276-2412 690 4013 276-2413 891 4017 276-2417 1.49 4020 276-2420 1.49 4021 276-2421 1.49 4023 276-2423 691 4027 276-2427 890 4028 276-2428 1.29 4046 276-2446 1.69 4049 276-2449 690 4050 276-2450 69C 4051 276-2451 1.49 4066 276-2466 990 4070 276-2470 690 4511 276-2447 1.69 4518 276-2490 1.49 4543 276-2491 1.99

SN-76477 Sound/Music Synthesizer IC

299 Featured in Oct. Popular Electronics

Creates almost any type of sound - music to "gunshots!" Built-in audio amp. Includes 2 VCO's, LF osc., noise gen.. filter. 2 mixers. envelope modulator, logic circuit. 28 -pin DIP. With data/applications circuits. 276-1765 .... .... 2.99

Analog Audio Delay IC MN 3002

For Phase -Shifter, Reverb & Delay Circuits "Bucket Brigade' device uses 512 shift registers to provide a continuously variable electronic delay for complex audio signals. Includes data sheet and applications circuits. 276-1760 10.95

CI TO -220. For PC board -mounted power semiconductors in TO -220 cases. Anodized aluminum. 276-1363 79C CI TO -3 Sink. For PC or chassis mtg. 276-1364 139 0 Universal. Mounts 2 devices, accepts 9 case styles. 276-1361 -. 2.69

Heat Sinks ' 0 'kk'

-

1 '

` '''.- ,

I E O \:-I\ ©

0

Top -Quality IC and PCB Accessories

8 :1 A

'110

O PC Board. Mounts two 14 or 16 -pin ICs or sockets for bread Dowding Copper clad. 21hx5x11hs. 276-151 2 99 m DC Board. Mounts single 14 or 16 -pin IC or socket. 276-024 Pkg. of 2/990 ® 16 -Pin IC Test Clip. 276-1951 3 99 O 16 -Pin DIP Header. With snap -on cover. 276-1980 1 29 33 8 -Rocket 16 -Pin DIP Switch. 276-1301 1.99 O Vertical 16 -pin Socket. For LED displays. 276-1986 1 49 041 16 -Pin DIP Jumper Cable. 18" long. 276-1976 3 99

Project Boxes

Aluminum Cover

The popular, low-cost way to house your electronic experiments.

31/4x2V.xl Mi. 270-235 1 19 4x24 x24 _ 270-231 1 29 5'I,6x21/4a14Y" 270-233 1 49 61/4a3402't 270-627 1 79 741 x477rx2ea 270-232 2 49

Miniature Hobby Motors

1.7 ?, a High -torque permanent

1112 magnet type. Its dia. shaft. O 12VDC.350mA.2x13116 273-210 69C

O 6-9V DC. 500mA. 16/6x3/4".

273-209 Pkg. of 2/990

CD

3

8080A Microprocessor and Support Chips

New - 100% Prime

All With Full Data and Specs

8080A Microprocessor. 2 µS cycle time. 276-2510 12.95

8208 Bus Driver. 8-bd bidirectional. 276-2508 5.95

8154 128x8 -Bit RAM 110. 40 -pin DIP. 276-2511 .. .... ... ... 9.95

8212 110 Port Data latch and butler. 276-2512. 4.95

8224 Clock and Generator Driver 276.2524.. .. . 3.95

8228 System Controller and Bus Driver. 276.2528... ... 6.95

8251 Programmable Communica- tion Interlace. 276-2551. 9.95

8255 Programmable Peripheral Inter- face. 276-2555. . 9.95

PC Potentiometers 21

Vertical

Horizontal

4 W. IF

Ohms

S00k 1k

5k 10k 25k 50k

1OOk

500k 1 Meg

Ca1

No

271-226 271.227 271-217 271-211

271-219 271-220 271.221 271-229

Al

Ea

490 49c 49C 49c --

49c 490 496 490

Cat No

271-333

271-335 271-336

271-338

E4

390

390 390

390

Custom Printed Circuit Board Kit

§_i' ns

-

Everything you need for making high - quality custom PC boards. 276-1576 7.95

Extra Resist Pen. 276-1530 1 29

Extra Etching Solution. 276-1535 2 19

Molded Connectors B

Molded nylon body. Each circuit rated SA

250V. Standard ,093- pin diameter, O+ 4 -Pin Male. 274-224 990

6 -Pin Male. 274-226 1 19

9 -Pin Male. 274-229 1 39 12 -Pin Male. 274-232 1 49

91 4 -Pin Female. 274-234 994 6 -Pin Female, 274-236 1.19 9 -Pin Female. 274-239 . 1 39 12 -Pin Female. 274-242 1 49

2 -Pin Male & Female. (Not Shown.) 274-222 Pair 890

IC Breadboard Sockets E

Modular boards snap together and feature standard 0.3" center. Accept 22 through 30 -gauge solid hookup wire. 04 550 connections in 2 bus strips of 40 tie points each with 47 rows of 5 connected tie points. 2'/ex6': 276-174 9.95 E 270 connections in 2 bus strips of 40 tie points each with 23 rows of 5 connected tie points. 21/ex33b'. 276-175 5 95

© Mini -Socket. 22 rows of 5 tie points each. plus 2 bus strips with 10

connections each. 21/ex17/e': 276-176 3 95

Digital Project Accessories

o 14 Bezel with Lens. Special high contrast filter for LED displays. 39/,6x1" lens opening. 270-301 3 95

191 Deluxe Display Case. Sleek molded case with red lens - mount up to four 0.6 or eight 0.3" LED digits. With bracket. 113/,6x37Ax47hd'. 270-285. 3 95

© MA 1003 Clock Case. For automotive clock modules. Ac-

cepts 3 pushbutton switches (not included). With bracket, blue lens. 31/2x2Vax2" 270-303 5 95

RAM Memory ICs Under 450 nS Access Time

2102 1024 x 1 Array. Low-cost static memory chip. 16 -pin DIP. Buy 8 and save! 276-2501 2 49 Ea. or 8/14.95

2114L 1024 x 4 Array. NMOS static RAM. 18 -pin DIP. 276-2504. 12.95

A

- 9

Computer Data Manuals and Semiconductor Handbook

13 Intel7° 8080/8085 Programming Manual. Handy reference for programming with Intel's assembly language. 62.1377 3.95

Ill Intel Memory Design Handbook. Explains use of Intel's memory components and support circuits in systems. 62-1378 3 95

© Intel Data Catalog. 928 pages of specifications on most of Intel's standard microcomputer -related products. 62.1379 4 95

O Semiconductor Reference and Application Hand - book. Complete specs and applications for popular IC

transistors, diodes. 276-4002 1 95

WHY WAIT FOR MAIL ORDER DELIVERY? IN STOCK NOW AT OUR STORE NEAR YOU! .

- III -

Prices may vary at individual stores and dealers

MC14553 3 -Digit BCD Counter IC

a

299 1

CMOS chip replaces over 8 separate IC's in a digital display circuit. Input pulse shaping. master reset pin. 16 -pin DIP. 276-2498 2 99

ad le' ShaeK A DIVISION OF TANDY CORPORATION FORT WORTH, TEXAS 76102

OVER 7000 LOCATIONS IN NINE COUNTRIES

APRIL 1979 101

11)


NEW -TONE ELECTRONICS INTERNATIONAL Original Japanese Replacement Parts for TV, Stereo and CB

25.UP 110d41 1-9 25 -UP I10 -24I 1-9 25-UP110d4 I 1-9 25 -UP 1 10-24 I 1.9 25-UP11044 11-9 25 -UPI 10-241 1-9 AN115 2.00 2.15 2.25 1470618 .85 1.05 1.15 U00857C 7.90 8.30 9.40 25C458 .18 23 .27 25C1096 a0 .50 .55 2502029 1.45 1.)5 1.95 AN2140 1.45 1.65 1.05 rA7062P 1.05 1.20 1.35 U80858C 5.90 6.20 6.90 25C460 .30 .35 40 25C1114 3.30 3.50 3.70 2562072 3.50 3.70 3.90 45234 5.04 5.51 6.00 r47063P .55 .65 .75 U80861C 7.80 920 9.30 251481 .90 1.10 .125 25C 11164 3.30 345 3.80 25C2076 .40 .55 .60 45239 4.10 4.30 4.00 17470748 2.40 2.60 2.80 254102 .20 .25 .30 25C482 .80 .95 1.10 25C1124 .75 .85 .95 2512091 .80 1.00 1.10 A 52471 2.40 1.60 2.90 747089P 1.80 2.10 2.30 354473 4s .55 .60 25C405 .95 1.15 1.30 25C1122 .75 .05 .95 75C2092 1.10 1.90 2.10 AN274 1.40 1.65 1.85 1470928 9.50 10.00 10.50 254484 1.20 1.40 1.60 25C495 .30 .40 .50 25C1162 .60 .70 .80 2512098 2.90 3.10 3.35 AN313 2.90 3,10 3.30 14712014 .85 .95 1.05 254495 .25 .30 .35 25C509 .25 .30 .35 2511166 20 .25 .30 25072 .45 .60 .65 AN315 1.75 1.95 2.20 7471398 1.55 1.75 1.95 25A509 .30 .35 .40 25C517 1.00 2.00 2.40 25C11728 3.00 3.50 3.85 76091 1.25 140 1.55 845114 1.60 1.80 2.05 TA7153P 5.70 5.90 6.10 25A562 .25 .30 .35 251535 .25 .30 .35 2501173 .45 50 .55 26092 1.25 1.35 145 84521 1.80 2.00 2.30 1472038 2.40 2.60 2.80 25A564 .25 .30 .35 25C620 .25 .35 .40 2561177 10.80 12.30 13.70 256178 .85 .90 1.05 11A1151 1.45 1.70 1.85 74)20414 1.90 2.10 2.40 254634 .35 .40 .45 25C6324 .30 .35 .40 25C1209 25 .30 .35 2513187 .30 40 .45 141156w 1,55 1.15 1.95 7472058 1.50 1.70 1.90 254636 .75 .95 1.15 2516344 .30 .35 .40 2511222 .20 .25 .30 250218 2.40 2.60 2.90 041306w 1.90 2.10 2.40 747214P 4.10 4.30 4.50 254643 .30 .35 .40 2566914 2.65 2.95 320 25C12264 .50 .55 .60 250234 .55 .65 .75 O 41322 2.10 2.50 2.00 1*73108 1.25 1.40 1.55 254673 .30 .35 .40 25C710 .18 25 .27 2511237 1.60 1.00 2.05 250235 .55 .65 .75 4413394 240 2.60 2.90 1476078 5.60 6.00 6.20 254678 .30 .35 .40 25C711 .18 .25 .27 2511239 2.00 2.55 2.75 250261 .30 .35 .40 HA1342 2.50 2.10 3.00 1476098 4.00 4.32 0.80 254683 .30 .35 .40 25C712 .18 25 .27 25C1306 1.30 1.45 1.60 250287 245 2.65 2.85 LA1222 1.50 1.55 1.60 113*8105 2.75 2.97 3.30 254604 .35 .40 .45 250717 .30 .35 .40 25C1307 1.85 2.05 2.35 250291 2.05 2.45 2,75 C03101 3.45 3.60 3.75 TC5081P 2.90 3.10 3.30 254695 .35 .a0 .55 25C730 2.80 3.00 3.20 25C1318 .30 .35 .40 250313 .55 .65 .70 L 44031 1.)5 1.95 2.20 7C5082P 3.30 345 3.80 2546994 .40 .50 .60 25C732 20 .25 .30 25C1364 .25 .35 .40 250315 .55 .65 .70 LA40328 1.75 1.95 2.20 TC9100P 7.54 0.02 0.50 254706 .80 .95 1.05 25C733 20 .25 .30 2561183 .25 .30 .35 260325 .55 .65 .70 644220 2.25 2.40 2.55 UH1C001 4.10 4.30 4.80 254720 .25 .30 .35 25C734 20 .25 .30 25C 1380 .25 .30 .35 250330 .55 .65 .70 LA4400 1.05 2.05 2.15 U01C002 4.10 4.30 0.80 2647450 3.60 3.80 4.20 256735 20 .25 .30 2511424 2.60 2?0 2.60 250356 .65 .75 .85 003141 1.70 1.80 1.90 U1111003 4.10 4.30 4.80 25872 25 .30 .35 25C7564 1.30 1.60 1.80 25C14484 .60 .70 .80 250358 .65 .75 .85 40511514 7.90 8.05 825 UH1C004 n.10 4.30 4.80 251354 20 .27 .30 25C761 .30 .32 .35 25C1a75 .60 .70 .80 250359 .75 .85 .95 6,51513L 2.00 2.20 2.50 U1411005 4.10 4.30 4.00 251377 .30 .40 .45 25C778 2.70 3.00 3.20 25C1509 .40 45 .50 250427 1.75 1.95 2.20 6N3001 13.75 14.85 16.50 UHIC006 4.10 0.30 0.80 2513175 20 .27 .30 250781 1.85 2.05 2.35 25C1567 .50 .60 .70 250525 .70 1.00 1.10 M 5300 9.62 1040 11.55 UPC20C 2.00 240 2.50 250186 .20 .27 .30 250784 25 .30 .35 25C1675 20 .25 .30 250526 .55 .65 .75 M53003 5.87 6.39 7.04 U8C141C 2.14 2.32 2.50 2513187 .20 .27 .30 25C/09 .75 .85 .95 25C1678 1.00 1.15 1.30 251119 .45 .50 .55 86601* 3.00 420 4.60 UPC 1574 3.25 3.45 3.65 258324 .25 .30 .35 251793 1.90 2.10 240 25C1681 .35 40 .45 2514234 .65 .75 .85 PLL02A 5.00 5.20 5.90 UPC5540 1.25 1.40 1.55 258367 .85 .95 1.10 250799 1.95 2.15 2.45 2501777 1.55 1.65 1.)S 250304 40 ,a5 .50 PLLOJA 7.60 8.00 8.80 UPCSSSH 1.25 140 1.55 258405 .25 .30 .35 ISC828 .20 .25 .30 25C1728 .60 .)0 .80 25033 .55 .65 .75 512644 6.24 7.02 7.80 UPC572C 345 3.55 3.65 7513407 .65 .40 .90 25C1129.20 .25 .30 25C1760 .65 .15 .85 25434 .45 .55 .60 66609 3.65 4.05 4.50 UPC574C 1.00 1.08 1,20 258463 .80 1.00 1.10 25C839 .25 .30 .35 2511)75 .30 .35 40 25041 .50 .55 .60 50613 5.20 540 5.95 17PC575C2 1.25 1.40 1.55 258474 .60 .70 .80 25C8674 3.10 3.30 3.60 2511816 1.35 1.60 1.80 25455 .60 .65 .75

5M5100 6.68 7.42 0.01 UPC576H 1.85 2.05 2.35 2513507 .70 .80 .90 256900 20 .25 .30 2501908 .25 .35 .40 2,35s5 :45235,28 1.35 1.55 1.75 ST K011 3.55 3.80 4.30 UPC59282 .65 .75 .85 258511 .60 .70 .85 25C930 20 .25 .30 2511909 1.60 1.80 2.10 25035 I.IO ].30 1.50 5T11013 7,40 7.60 6.60 U8C1001H21.85 7.05 2.35 258551 1.60 1.85 2.30 250945 .20 25 .30 2511945 4.30 4.80 5.20 35037 1.)0 2.00 2.30 500015 4.00 420 4.70 UPC1008C 4.10 .430 4.80 25C183 .30 .40 .50 25C10008L .30 .40 45 25C1957 .50 .60 .70 3SK40 .35 1.05 1.15 STIS050 23.10 25.98 28.86 UPC 1020H 1.85 2.05 2.35 251184 .30 .40 .50 2561013 .50 .60 .65 25C1969 3.40 3.80 4.20 351141 1.25 1.40 1.55 5TISa15 7.10 7.60 8.10 U86102514 1.85 .205 2.35 254372 .18 .25 28 25C1014 .45 .60 .65 25C19)3 .60 .65 .70 35445 125 1.40 1.55 ST0435 4.40 4.90 5.50 UPC1028H 140 1.62 1.80 251373 20 .25 .30 25C1018 .50 .60 .70 25C1974 1.70 1.60 1.80 35048 3.30 340 3.70 5114439 7.60 7.90 8.30 UPC1031H 2.52 2.74 2.98 25C380 .18 .25 .28 25C1030 1.70 2.00 .230 25C1975 1.20 1.60 1.80 351449 125 140 1.55 747045M 1.90 2.10 2.40 UPC115211 2.90 3.10 3.30 25C182 .30 .35 .40 25C1056 4.30 4.50 4.10 25C2009 .70 .75 .80 TA7055P 1.90 2.10 240 UPC1156H 1.85 2.05 2.35 750387* 27 .35 .40 2511060 .65 .75 .85 2502021 .50 .55 .60 147060P .65 .75 .85 17P13277C 8.70 8.90 9.10 25C 394 .18 .23 .27 25C1061 .65 .75 .85 25C2028 45 .50 .55

Minimum Order 510.00 - N.J. Residents add 5% Sales Tax. We Pay postage for prepaid orders of 550.00 or more,

Under S50.00, add S1.00, Canada 51.50. Quantity Discount Prices - Ask for our complete price list -

Manufacturer inquiries welcome - All parts guaranteed. Prices flay change without notice. C.O.D. orders welcomed.

TOLL FREE TELEPHONE Nationwide 800/631.1250 Local 201/748-5089

In New York 212/732-1376

IMMEDIATE DELIVERY WITHIN 48 HOURS

ON ALL PARTS IN STOCK


NEW -TONE ELECTRONICS INTERNATIONAL P. O. Box 1738, Bloomfield, N. J. 07003

New Jersey Phone: 201/748-5089 Monday thru Friday 8:30 to 5:30

CODE -A -PHONE

Telephone Answering Devices Wiremote

.YJuJI Command

Modd 1400 199 95 ?,:,;;;'$249.95,,s/ :KPRECISION

Service Master Attache Style

" Tool Kit Tool Cases odr.

Model 99SM MODEL IC 100/ST º9PR

$42.95 S.s, 57g1110 Roll Kit

$269.95 $15.95

=MG 20 MHz. ---,-..1.-1---

Logic Probe Dual Trace Model LP 440 en.lt 90n 1 ..a.- I N 16 1 97 11,11,5719 9h

6611' í1.1111P»1....,4 $40.00 .I1n,t,.. 84ee'.Im' $654.50 OH , 50 eSe complete 11 s á.s,, '.,. 1.es'

. M1n01Niii.'1.~9'unn..It OIL 111 _ M' 1 1

_sea a-ee45011e1

EtVCOFRE POCKET CRICKET

TRANSISTOR/FET TESTER Req 517500 $99.95

Magnifier - . 700 Series LAMP ¡y

,

...111,911111.10 00,11.4

Model MG 100 »11I 9 L"' ie 1

KPRECISION . SUPER SPECIAL \ Model

1827

30MHz $49.50

3%2 -Digit Portable DMM . 0...6e94 Á.o . e.ne' n1 Al ,e.n.i.3 1pnIEDO1w'.r .41.eolno..,g Model 2800

Model 2810 $11 0.50

D 15 MHz Mini Oscilloscope

Model MS 15

Reo 5318 00

$269.95

r

, 1' ."fll,,',, Pow U' 'l O

NOW AVAILABLE '

Dual Hare Version $369.9 5 Model MS 215 Roil $435 00

.sue=

Ungar Heat Gun Req 565 00

$46.50

17r_*

S E= NJ C ORE TV-VTR-MATV and Video Analyzer

r-:<. C9

1 `3 Model

_ _, '1 ° VA48 ir $875.00575011_

Weller XCellte

,>

l w`

, ,, ..,

LEADER Insturninle Corp

Model l80 508

I Portable ° Auto Stereo -till Watt ° VOM Multimeters Frequenc

Power Booster 20K ohm/v $19.95 , POW -40 Reg

53995$24.95

1K ohm/v, 9.95

Counter Transistor Tester Model 100 Req. slzn.on º.116.5 7 $22.00

I $59.95 .61. .e.. 1..m n

/ ICI 1018."d,á 1.1

855R Conklin SI Farmingdale N v 11735

- CONTINENTAL SPÉUACIICJ

7u '

100 MHz 8 -Digit Counter $119.0$119.00-Ma...$119.00-Ma... Kr N. 11111 MH. ry. 6 111111 '.1. .

' Model NOw'AvmI4We PS500500MHZ Prescaler $52.95

Digital Capacitance Meter

PKPRECISION

Model 820

LEADER ----.--lb Model LCR 740

s

-A 27195

WAHL NEW ISO -TIP "Quick Charge

Logic Monitor 1 d 11 \I

Fin Î1l P14 CMOS 16110 nnu'n 6r1 111dn.9" $52.95e 'w

PModel LM l ImPlete

Flinn

Attach Tool -.. Case with 2 Removable Pallet Mode1600$ $65.00 Req S09.009134

$27.95 Model 7500 Catches

Soldering loon 517.95

Model 5800 15911114 SP

Cnod Tesler S22.50

In -Dash AM/FM 8 Track Sub - Stereo' - stitution

(WPW ;Box$51

Hlj Function Generator

0.777

$52.50 Model 2910

MODEL

Transistorized LCR Bridge

MAX 100 1u

BSR Changer Accessories

. $24.95

858 17` -

20 or cel4nne magnet

$14.95 MPRECISIt7M 15MHz 3" Dual Portable Trace Scope :gibs4 Model 14328

Req 5780.00

$663. wdh Prohn

Weller Controlled $45.00

Output Rey 57500

Soldering Mode1WTCPN

Station FREE

`""`°°'°""' Catalog AM/FM Call TOLL FREE .its Cassette (800) 645-9518 000 900

Igo Ne Side 1 , .5 6' . 52 0054 " GAS BOB Stereo $57.50

Exila 511 8o11. 51.1. ' 'n.ae9' u od.mn N n,.,.



SUPER a

1313ELF

.a

RCA Cosmac Super Elf Computer $106.95 Compare features before you decide to buy any

° other computer. There is no other Computer on

the market today that has all the desirable bene-

fits of the Super Elf for so little money. The Super Elf is a small single board computer that does many big things. It is an excellent computer for training and for learning programming with its machine language and yet it is easily expanded with additional memory, Tiny Basic, ASCII Keyboards, video character generation, etc.

The Super Ell includes a ROM monitor for program loading, editing and execution with SINGLE

STEP for program debugging which is not in-

cluded in others at the same price. With SINGLE STEP you can see the microprocessor chip operating with the unique Quest address and

data bus displays before, during and after executing instructions. Also. CPU mode and in-

struction cycle are decoded and displayed on nine

LED indicator lamps.

An RCA 1861 video graphics chip allows you to

connect to your own TV with an inexpensive video modulator to do graphics and games. There is a

speaker system included for writing your own music or using many music programs already written. The speaker amplifier may also be used to drive relays for control purposes. A 24 key HEX keyboard includes 16 HEX keys

Super Expansion Board with This is truly an astounding value! This board has

been designed to allow you to decide how you want it optioned. The Super Expansion Board comes with 4K of low power RAM fully addressable anywhere in 64K with built-in memory protect and a cassette interlace. Provisions have

been made for all other options on the same

board and it fits neatly into the hardwood cabinet

alongside the Super Elf. The board includes slots for up to 614. of EPROM (2708, 2758, 2716 or TI

2716) and is fully socketed. EPROM can be used for the monitor and Tiny Basic or other purposes.

A IK Super ROM Monitor 519.95 is available as

an on board option in 2708 EPROM which has

been preprogrammed with a program loader/ editor and error checking multi file cassette read/write software. (relocatible cassette file) another exclusive from Guest. It includes register save and readout. block move capability and

video graphics driver with blinking cursor. Break

points can be used with the register save feature

to isolate program bugs quickly, then follow with single step. The Super Monitor is written with subroutines allowing users to take advantage of

monitor functions simply by calling them up. 8 0Z111 n

Auto Clock Kit $15.95 DC clock wdh 4-.50" displays. Uses National MA -1012 module with alarm option. Includes

light dimmer, crystal timebase PC boards. Fully

regulated. comp. instructs. Add $3.95 for beau-

tiful dark gray case. Best value anywhere.

RCA Cosmac VIP Kit $229.00 Video computer with games and graphics. Fully assem. and test. 5249.00

Not a Cheap Clock Kit $14.95 Includes everything except case. 2 -PC boards. 6-.50" LED Displays. 5314 clock chip, transformer. all components and full instructions. Orange displays also avail. Same kit w/.80" displays. Red only. 521.95 Case $11.75

60 Hz Crystal Time Base Kit $4.40 Converts digital clocks from AC line frequency to crystal time base. Outstanding accuracy. Kit

includes: PC board, IC. crystal. resistors. ca-

pacitors and trimmer.

TERMS:

II

plus load, reset, run, wait, input, memory protect, monitor select and single step. Large, on board displays provide output and optional high and low address. There is a 44 pin standard connector for PC cards and a 50 pin connector for the Quest Super Expansion Board. Power supply and sockets for all IC's are included in the price plus a detailed 90 page instruction manual.

Many schools and universities are using the

Super Elf as a course of study. OEM's use it for training and research and development.

Remember. other computers only offer Super Elf

features at additional cost or not at all. Compare before you buy. Super Elf Kit $106.95, High

address option $8.95, Low address option S9.95. Custom Cabinet with drilled and belled

plexiglass front panel $24.95. NiCad Battery Memory Saver Kit $6.95. All kits and options also come completely assembled and tested. Ouestdata, a 12 page monthly software publication for 1802 computer users is available by sub-

scription for $12.00 per year.

Tiny Basic for ANY 1802 System Cassette 510.00. On ROM $38.00. Super Elf

owners, 30% off. Object code listing with manual 55.00. Object list, manual and paper tape

$10.00. Original ELF Kit Board 514.95.

Cassette Interface $89.95 Improvements and revisions are easily done with

the monitor. If you have the Super Expansion Board and Super Monitor the monitor is up and

running at the push of a button.

Other on board options include Parallel Input and Output Pods with lull handshake. They

allow easy connection of an ASCII keyboard to the

input port. RS 232 and 20 ma Current Loop for teletype or other device are on board and i1 you need more memory there are two 5-100 slots for static RAM or video boards. A Godbout PK RAM

board is available for $135.00. Also a 1K Super Monitor version 2 with video driver for full capability display with Tiny Basic and a video interface board. Parallel I/O Ports 59.85. RS 232 $4.50, TTY 20 ma I/F 51.95, S-100 $4.50. A 50 pin connector set with ribbon cable is available at

$12.50 for easy connection between the Super Elf and the Super Expansion Board.

The Power Supply Kit for the Super Expansion Board is a 5 amp supply with multiple positive and negative voltages 529.95. Add $4.00 for shipping. Prepunched frame $5.00. Case

S10.00. Add $1.50 for shipping.

Digital Temperature Meter Kit Indoor and outdoor. Switches back and forth. Beautiful. 50" LED readouts. Nothing like it

available. Needs no additional parts for com- ^ plete, full operation. Will measure - 100' to

4-200 F. tenths of a degree, air or liquid. Very accurate. 539.95 Beautiful woodgrain case w/bezel $11.75

NiCad Battery Fixer/Charger Kit Opens shorted cells that won't hold a charge and then charges them up, all in one kit w/lull parts and instructions. $7.25

PROM Eraser Will erase 25 PROMS in

15 minutes. Ultraviolet, assembled $34.50

Rockwell AIM 65 Computer 6502 based single board with full ASCII keyboard

Same day shipment. First line parts only

Factory tested. Guaranteed money back.

Quality IC's and other components at fac-

tory prices.

INTEGRATED CIRCUITS

7400771 74006 74026 7404N 74099 741011 74145 74209 74224 74304 14429

74456 74476

7.14811

74509 74749 74756 74856 74899 74906 74926 74935 74956 741009 741075 741219 741239 7412511 741455 74505 741,519 741546 741576 141616 141626 741639 741749 741759 744909 741925 741936 7422111 742969 743655 7436616

743679

741500 M. 7415006 1415026 7415049

7415059 741.5089 7415105 74L513N 7415149 7415208 7416229 7413286 7411309 7/15339 7415366

94 1415746 1415159 7415906 1415939 7405959 14151074 74151125 74051139 74151326 74111309

74151514 14151556 741.91579 74151625 7415163x 74151749 74151909 7415.2215 74052544 7115362N

and 20 column thermal printer. 20 char. al-

phanumeric display, ROM monitor. fully expandable. $375.00. 4K Assembler S85.00. 8K Baste

F Interpreter $100.00. Power supply assembled in case $60.00.

$5.00 min. order U.S. Funds. Calif residents add.6%tax. BankAmericard and Master Charge accepted. Shipping charges will be ,added on charge cards

1-1"

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P.O. Box 4430C Santa Clara, CA 95054

For will call only:(408) 988-1640 2322 Walsh Ave.

054553 3 50

004566 2 25

cÓ15És 118 0040197 3 00 7C00 28 7.004 33

7.010 .28 7.C14 210 I4C20 28 74030 1D

74c740

95

71C76 1 741

71090 71093 140154 710160

710175 741192 740221 71[905 7J£905 740914 7,C922 74C923 74C925 74L926 741921

INTERFACE 9095 1096 7097 1098

8710 6113 1120 5723 6124 8025 8726 1128 1797

8791

I 15

1 40

300 I 44 I 35 I 65 2 00 300

]5 1 95 550 550 6 91 6 95 6 95

65 65 65 65

I 25 4 50 300 550 3 10

350 3 20

69 2 75 1 69 1 69

M05/MEMORY NAM 21011 3 95 7102.1 95

210241.4 I 60 21702 1 25 210464 4 95 21076 4 95

21111 3 15

21722 395 2114 8.50 4116 12.95 15138 6 30 311021 1 29 11115262 40

9M5280 300 14115320 995 8191330 594 '04110.3 4 00 P01110.4 5 00 951011 13 95 4-004 9 95 92525 2 90 911.020 I 50 6001655 6.95 9457100 4 50

GIAY38500 1 9.95 90465714 995

9368 3.50 00 10 00

416 16 00

CLOCKS 941309 300 1.195311 3 60 9M5312 460 9145313 3 60 995314 7.90 995315 400 M45316 S 00 695310 360 9145369 21D 14145641 14 45

MM5865 7 95 CT7001 S 60 CT1002 8 95

T715 Í 35C70

M953750.6 390 955315AB N 4 90

1205 16 50 7207 7 50 7208 15 95 7209 4 95

050026L8 3 75 05005606 3 75 81953104 2 50

MICROPROCESSOR 6600 1 50

6802 24 95 80604 405 aura 895 8085 27 00

47 2808 19 75

440 é21í4 800

i 2

4 8224 2 9200

94 8228 5 35

2 120 é22113 10 000

8155 9 25

1 02 8257 19 50 1259 19 50 007180200 19.95

21m

21

1 51

79

Multi -voltage Computer Power Supply 4

8v 5 amp, _ the .5 amp, 5v 1.5 amp, -Se .5 amp, 12v .5 amp. -12 option. =5v, _l 2v

are regulated. Kit $29.95. Kit with punched frame

$34.95. Woodgrain case $10.00.

Video Modulator Kit $8.95 Convert your TV set into a high quality monitor without affecting normal usage. Complete kit

with full instructions.

2.5 MHz Frequency Counter Kit Complete kit less case 537.50

30 MHz Frequency Counter Kit Complete kit less case 547.75 Prescaler kit to 350 MHz $19.95

79 IC Update Master Manual $3500 Complete IC data selector. 2500 pg. master ref. '

erence guide. Over 50.000 cross references. Free

update service through 1979. Domestic postage $3.50. Foreign $5.00. 1978 IC Master closeout 619.50.

COP10020 COP1161 6820 6150 6502

ELECTRONICS

2500 2 95 9 95

12 95 12 50

IC SOCKETS Solder Tin Low Prol9e RN IUP PIN IUP

8 15 22 30

14 IA 24 25 16 20 28 42 18 22 36 58

20 29 40 .57 3re raw We

N

WIRE WRAP LEVEL 3

PIN PIN 14 25 23 46 16 33 28 100 i8 57 40 123

DART/F110 AY5.4013 AYS 1011 3341

PROM 1702A 982513

6825123 6825126 9025129 9825131 9825436 6112513' 2708 098577 6123 271611 2716 Intel

CRYSTALS I AM, t

11 4MN1 59H/

10 1419

11MH1 20 914 32 WO 12768 1161 18132MHz 3 5195 MHz

2 0100 M57 2 097152 95/ 2 4576 61111

3 2768 Mlle 5.0658 957 5 185 MW 57M34W 6 5536 910 14.31816 M117

18 432 457 221184 916

rekkicreks aa Lan edge 275 TRANSFORMERS

100 010 edge 4.50 64 300 54 3.25

100 ,1 edge WW 5 25 12 Von 300 malransrormer 125 12 64 C7 600 ma 3 75

e9920Á60 ENCODERS 1Ñ CT 250 m211walil gpl 350 4653606 912 50 246 CT 400 ml

W 395

7409 t 350 IN 12 amp rail plug 4 115 740922 5.ío 12V64mp 1295 040 5 9O

001655 6.95 13661RY 1105 CA 70

IC Tell 01101 65353 a 1 7.90

25

10 94970/74 CA/CA 300 100 Red 55 47 01704 CC 300 125 Black 55 47 01.707,O1707R CA 300 100

Meyer 8043 54 50 012 7i5Ó MCC 6600 195 comp w/Ip4./0994 00750 CC 600 195

880359 CC 357 70

i90500 507 COCA 500 735 45 F90501510 CC/CA .500 90

1X0100.607 CCICA .800 2 20 60

5.50 / 50 6 95

3 95 2 95 3 50 3 75

3 75 7 75 8 75

8 75

1050 2 90 2 90

CLOCK MODULES Compete alarm noses medy to hook up mlh transformer and

s2Rclws Very e9mp10 with 50' and 84 shorts 911001A. or E.50 8.95 10283 Tranetormer 2.25 MA1010/. C o, E .8d 11.95

10272 75114ormel 225 Specul Innslarmer and sle

-R00 wh

en pumneeed

041module 2.95

803 par module l green duo,, display 15.95

RESISTORS 4, wan 5-. 10 per type 03 1000 per lyre 012 25 Per We 025 350 piece 0401

100 per type 015 5047 type 675

KEYBOARDS 56

1ík ,7 ASCII keyboard board 511 567 50

7 50

53 key ASCII 17950114 40 60 00 dolly asºm08c 70 CO EMOsure 54 95

LEDS Red 1018 15

Green. Yellow 7018 20

Jumbo Rea 20 Green. range yellow Jumbo 25 0110144 LEO Mounting Cnps 811 25

(sou./red amber.41een W140 ereerl

CONTINENTAL SPECIALTIES In 6465 Compki1/9cof weerb ardten e9u,p 460.100 1 MN Ere9. CIr. 5121.95

06 WIRE WRAP TOOLS in trace Pcnabie MUllime5er 511.00

DIGITAL THE790ME7ER 518.50

1/8-1151 n pe1 (:erwlal purDpº4pr memea

32 -230 E 01iD0vMe pr 9e co - 2 1ccY clomp nAss In

r4 w1144ullsYwn F c

COMPUTER BOARD KITS 29 50 86 RAM Borre Ke $135 CO

08 00 41 EPROM ad 114.95 00 60410 141 44 50

&rende5 Bunt wrconneo41 12 50 766 EPROM bran/ Mr ono PROMS 74 50 4 50

4 50 ; 25

25 4 25 3 90 3 90 390 4.00 4 50 I 20 1 95 4 50 450 4 50 4 50 4 50

4 50

a 25 4.50 4 50

TRANSISTORS 261863 2522224 297369 2629008 21129074 263053 763638 293643 293904 263906 263055

294401 264402 11831 0,7334

18

20

aÓ

25

25 18

15

69

25

60

lao

Non6 Stn Flood/ 071 RR 5065.00 40000147 Orne Ne 5

SPECIAL 780000T500 ó495865 Stopwatch 7,me, 9.00 PO bears 750 Swnche6 Mom Pusn8ut105 27

3 pot slide 25 Encoder 5001656 6.95 3 D198 Universal Counter Board K8

Opines 5 8 DC b 5 1Á H0

9p 125 LED rs5la9 10.50 Voice !dueled switch .50

7I11116,164 1001 10014 MFI9Fer Kit 5224.00 Model 10 logger

E4wnder 65 5229 00 Model ISO Bus

Grl8ber 641 5369.00 Sinclair 319 Digit

Mulllmeler 159.95 Clues Calendar 611 123.95

3 eqn 4 0107

045016

DGB Fluorescent 3610 Fluorescent

1.75 1.75

61699 45'3,8019 160 7520 Clue. pn4locells 39 TI1311 Mea 9 50

COMPUTER GRADE CAPS

1600 pia 2009

2000 mid 459 3200 '09 5500 254 5800 409

0 0,7,8,,,,, RS232 6100 25 Pn Su0mn41u,es 7700 09256 2 95 8000 05255 3 95 9400 Cover 1 50 85232 Compele Set 650 1 DE97 150 35000 DE95 1.95 55000 0415P 2 10 92000 04155 3 10 60000

506 509 554 654 20V 306 25V 254 15V 104

4.50 2.50 2 50

250 300 300 3.00 250 2.50 300 250 3 50 500 5.00 6.00

4.00

Stopwatch Kit $26.95 Full six digit battery operated. 2-5 volts.

3.2768 MHz crystal accuracy. Times to 59

min., 59 sec.. 99 1/100 sec. Times std., split and Taylor. 7205 chip, all components minus case. Full instructions.

Hickok 31/2 Digit LCD Multimeter Batt/AC oper. 0.1 mv-1000v. 5 ranges. 0.5% actor. Resistance 6 low power ranges 0.1 ohm -20M ohm. DC corn. .01 to 100ma. Hand

held, I/z" LCD displays, auto zero, polarity, over - range. $74.95.

S-100 Computer Boards 8K Static RAM Kit S135.00

16K Static RAM Kit 265.00 24K Static RAM Kit 423.00 32K Dynamic RAM Kit 310.00 64K Dynamic RAM Kit 470.00 BK/16K Eprom Kit (less PROMS) $89.00 Video Interface Kit 5139.00 Motherboard S39. Extender Board $8.99

FREE: Send tor your copy of bur NEW 1979

QUEST CATALOG. Include 28Q stamp.

r m n mi

23

0

CIRCLE NO. SOON FREE INFORMATION CARD


QTY. DIODES/ZENERS

1N914 100v 10mA .05 1N4005 600v 1A .08 1N4007 1000v 1A .15 1N4148 75v 10mA .05 1N4733 5.1v 1 W Zener .25 1N753A 6.2v 500 mW Zener .25 1N758A 10v .25 1N759A 12v .25 1N5243 13v " .25 1N5244B 14v .25 1N5245B 15v .25

QTY. SOCKETS/BRIDGES

8 -pin pcb .20 ww .35 14 -pin pcb .20 ww .40 16 -pin pcb .20 ww .40 18 -pin pcb .25 ww .95 20 -pin pcb .35 ww .95 22 -pin pcb .35 ww .95 24 -pin pcb .35 ww .95 28 -pin pcb .45 ww 1.25 40 -pin pcb .50 ww 1.25 Molex pins .01 To -3 Sockets .25 2 Amp Bridge 100 -pry .95 25 Amp Bridge 200 -pry 1.50

QTV. TRANSISTORS, LEDS, etc.

2N2222 (2N2222 Plastic .10) .15 2N2222A .19 2N2907A PNP .19 2N3906 PNP (Plastic Unmarked) .10 2N3904 NPN (Plastic Unmarked) .10 2N3054 NPN .45 2N3055 NPN 15A 60v .60 T1 P1 25 PNP Darlington 1.95

LED Green, Red, Clear Yellow .15 D.L.747 7 seg 5/8" High com-anode1.95 MAN72 7 seg com-anode (Red) 1.25 MAN3610 7 seg com-anode (Orange) 1.25 MAN82A 7 seg corn -anode (Yellow) 1.25 MAN74 7 seg corn -cathode (Red) 1.50 FND359 7 seg.com-cathode (Red) 1.25

QTY. 9000

9301 .85

SERIES QTY.

9322 .65 9309 .35 9601 .20 9316 1.10 9602 .45

MICRO'S, RAMS, QTY.

8T13 1.50

CPU'S, E -PROMS QTY.

21078-4 4.95 8T23 1.50 2114 9.50 8T24 2.00 2513 6.25 8T97 1.00 2708 10.50 745188 3.00 2716 D.S. 34.00 1488 1.25 2716)5v) 59.00 1489 1.25 2758 (5v) 23.95 1702A 4.50 3242 10.50 AM 9050 4.00 4116 11.50

6800 13.95 MM 5314 3.00 6850 7.95 MM 5316 3.50 8080 7.50 MM 5387 3.50 8212 2.75 MM 5369 2.95 8214 4.95 TR 16028 3.95 8216 3.50 UPD 414 4.95 8224 3.25 Z 80 A 22.50 8228 6.00 Z 80 17.50 8251 7.50 Z 80 PIO 10.50 8253 18.50 2102 1.45 8255 8.50 2102L 1.75 TMS 4044 9.95

C MOS QTY.

4000 .15 4001 .15 4002 .20 4004 3.95 4006 .95 4007 .20 4008 .75 4009 .35 4010 .35 4011 .20 4012 .20 4013 .40 4014 .75 4015 .75 4016 .35 4017 .75 4018 .75 4019 .35 4020 .85 4021 .75 4022 .75 4023 .20 4024 .75 4025 .20 4026 1.95 4027 .35 4028 .75 4029 1.15 4030 .30 4033 1.50 4034 2.45 4035 .75 4037 1.80 4040 .75 4041 .69 4042 .65 4043 .50 4044 .65 4046 1.25 4048 .95 4049 .45 4050 .45 4052 .75 4053 .75 4066 .55

4069/74C04 .35 4071 .25 4081 .30 4082 .30 4507 .95 4511 .95 4512 1.10 4515 2,95 4519 .85 4522 1.10 4526 .95 4528 1.10 4529 .95

MC 14409 14.50 MC14419 4.85

74C151 1.50

QTY. MCT2

LINEARS,

.95

REGULATORS QTY.

LM323K 5.95 8038 3.95 LM324 1.25 LM201 .75 LM339 .75 LM301 .45 7805 1340T5) .95 LM308 .65 LM340T12 .95 LM309H .65 LM340T1 5 .95

LM309K (340K-5) 1.50 LM340T18 .95 LM310 .85 LM 340T24 .95 LM311 D .75 LM340K12 1.25 LM318 1.75 LM340K15 1.25 LM3201116 .79 LM340K18 1.25 LM 320 H 15 .79 LM340K24 1.25 LM320H24 .79 LM373 2.95

7905 (LM320K5) 1.65 LM377 3.95 LM320K12 1.65 78L05 .75 LM320K24 1.65 78L12 .75 LM320T5 1.65 78L15 .75 LM320T12 1.65 78M05 .75 LM320T1 5 1.65

, etc. QTY.

LM380 (8-14 Pin)1 LM709 (8-14 Pin)

LM71 1

LM723 LM725 LM739 1

LM741 (8-14) LM747 1

LM1307 1

LM 1458 LM 3900 LM75451 NE555 NE556 NE565 NE566 1

NE567

QTV. -

QTV T T L -

QTY.

7400 .10 7482 .75 74221

7401 .15 7483 .75 74367

7402 .15 1485 .55 75108A 7403 .15 7486 .25 75491

7404 .10 7489 1.05 75492

7405 .25 7490 .45 74H00

7406 .25 7491 .70 74H01

7407 .55 7492 .45 74H04

7408 .15 7493 .35 74H05

7409 .15 7494 .75 74H08

7410 .15 7495 .60 74H10

7411 .25 7496 .80 74H11

7412 .25 74100 1.15 74H15

7413 .25 74107 .25 74H20

7414 .75 74121 .35 74H21

7416 .25 74122 .55 74H22

7417 .40 74123 .35 74H30

7420 .15 74125 .45 74H40

7426 .25 74126 .35 74H50

7427 .25 74132 .75 74H51

7430 .15 74141 .90 74H52

7432 .20 74150 .85 74H53

7437 .20 74151 .65 74H55

7438 .20 74153 .75 74H72

7440 20 74154 .95 74H74

7441 1.15 74156 .70 74H101

7442 .45 74157 .65 74H103

7443 .45 74161 .55 74H106

7444 .45 74163 .85 74L00

7445 .65 74164 .60 74L02

7446 .70 74165 1.10 74L03

7447 .70 74166 1.25 74L04

7448 .50 74175 .80 74L10 7450 .25 74176 .85 74L20 7451 .25 74180 .55 74130 7453 .20 74181 2.25 74147 7454 .25 74182 .75 74L51

7460 40 74190 1.25 74155

7470 .45 74191 1.25

.75

74172

7472 .40 74192 74173

7413 .25 74193 .85

_95 .95

74174

74175

74193

7474 .30 74194

74195 7475 .35

7476 .40 74196 .95 74L123 7480 .55 74197 .95

1.45

741500 7481 .75 74198 741501

INTEGRATED CIRCUITS UNLIMITED

QTV.

1.00 741502

.95 74 LS04

.35 741505

.50 74LS08

.50 741509

.15 741510

.20 741511

.20 741520

.20 741521

.35 741522

.35 741532

.25 74 LS37

.45 741538

.25 741540

.25 741542

.40 741551

.20 741574

.25 741576

.25 74 LS86

.25 741590

.15 74LS93

.25 743107 .20 7419123 1

.35 7415151

.35 7419153

.75 7415157

.55 7415160

.95 7415164 1

.25 7415193 1

.20 7415195

.25 7415244 1

.30 74 LS367

.20 7415368

.35 74S00

.45 74502

1.95 74S03

.45 74504

.65

.45

.40

74505

74508

74510

.45

.85

.55

74S11

74S20

74S40

.85 14550

.30

.30

7889 Clairemont Mesa Blvd., San Diego, California 92111 24 Hour Toll Free Phone 1-800-854-2211

(714) 278-4394 California Residents 1-800-542-6239 CABLE ADDRESS ICUSD CUSTOMER NAME

STREET ADDRESS

CITY STATE ZIP

PHONE CHARGE CARD #AE BA MCa EXP. DATE

74551

74564

74S74

745112

745114

745133

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74S151

749153

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SPECIAL DISCOUN

Total Order Dedi

COD WILL CALL UPS POST NET 10th OF THE MONTH PO N $35-$99 10`.

ALL ORDERS SHIPPED PREPAID - NO MINIMUM - COD ORDERS ACCEPTED - ALL ORDERS SHIPPED SAME DAY $100-$300 15 OPEN ACCOUNTS INVITED - California Residents add 6% Sales Tax. PRICES SUBJECT TO CHANGE WITHOUT NOTICE. $301-$1000 20`.

We accept American Express / Visa / BankAmericard / Master Charge CIRCLE NO. 32 ON FREE INFORMATION CARD


Operation Assist It you need information on outdated or rare

equipment -a schematic. parts list. etc. -another reader might be able to assist. Simply send a postcard to Opera- tion Assist. POPULAR ELECTRONICS. 1 Park Ave.. New York. NY 10016. For those who can help readers. please respond directly to them. They'll appreciate it. (Only those items regarding equipment not available from normal sources are published.)

Electronic Design Corp., Victrola amplifier model 80-12C. Need source for information. W. Wyatt Miller, 305 W. Dia- mond Ave., Gaithersburg, MD 20760.

Hallicraftere Sky Buddy receiver and RCA R-65/APN-9 re-

ceiver indicator. Schematics. Ted K. Wright, 3929 Wood - lane. Ft. Worth, TX 76117.

Knight Kit model C22 CB transceiver. Schematic and operating instructions. William Pence, 800 Old Stage Rd., Cave Junction, OR 97523.

National Union Osdllograph Co., type B3-5 oscilloscope. Instruction manual. Bruce W. Miller, Box 21963, Seattle, WA 98111.

Devry Technical Institute combination oscilloscope VTVM from 1959 home study courses. Assembly manual and schematic. D. Moore, Box B3, Main St., Aylestord. N.S. Canada, BOP 1C0.

Sansul model 1000A tuner amplifier. Operating manual and

schematic. Paul Shelton. 9004 E. 29th Pl., Tulsa, OK 74129.

RCA CB 2608A, serial NO2. Schematic and tube list. F. C.

Bergquist, 105 Ellis St., Leesville, LA 71446.

Stromburg Carlson radio model 642A. Schematic and owners manual. James Olin, 720 E. Harbor Dr. S, St. Petersburg, FL 33705.

Precision model 120 -volt -ohm meter. Schematic. Alex R.

Minelli, 718 Michigan St., Hibbing, MN 55746.

Heathklt model HWA-202-2 tone burst encoder module for

HWA-202 two -meter transceiver. Manual or kit. Gary Resta, 20C Tindal Lane, Niagara Falls, NY 14304.

Bradford model WTG-59816 tape recorder. Schematic and any other information. Earl Stephenson, 1956 Minnesota Ave., Columbus, OH 43211.

Lafayette HA 350 receiver. Schematic and instruction manual. Bud Benson. 976 E. Lawson St., St. Paul, MN 55106.

Lafayette KT -320 receiver. Schematic and operating manual. L T. Switzer, 654 Georgia, Marysville, MI 48040.

Singer model HE8121 television. Schematic, diagrams and operating manual. Charles Peklenk, 12939 Tosca, Houston, TX 77024.

Sonic guitar amplifier. Schematic. Roger Gran, 225 S. 7th

St., La Crosse, WI 54601.

Jackson Electric Instrument Co., model TVG-1 TV signal and sweep generator. Schematic and operating instructions. Don Schultheis, 3746 Garfield Ave., Pennsauken, NJ 08105.

Atwater Kent model 60C radio receiver. Schematic, service manual. David G. Ford. 906 Ida, Victoria, TX 77901.

Sprague Teleohmike capacitor analyzer model TO -4 and Heathklt model AV -3 audio VTVM. Service manuals, calibration data and schematics. E. J. Prado, Box 75591, Los Angeles. CA 90005.

Lafayette model 99-50775 power supply. Schematic needed. David Edlund, 2923 N. Stevens, Tacoma. WA 98405.

RCA model WR-39C TV calibrator. Operation manual. Bob Brandel, Rose Hulman Institute of Technology, Box 927, 5500 Wabash Terre Haute, IN 47803.

Fairchild channel F system II video game. Schematic. S. T.

Stickle, 651 E. Travis Blvd *14, Fairfield, CA 94533.

Radio City Products model 664 VTVM. Schematic and manual needed. H. T. Finch, 6158 Winton, Dallas, TX 75214.

Hammerlund HQ -110A. Operating manual needed. Paul Migliore, N2AKO, 710 Cookman Ave.. Asbury Park, NJ

07712.

APRIL 1979

RCA model MI -11940 tape drive unit. Need service manual

or any other information. James J. Julian. 850 Broad St.,

Teaneck. NJ 07666.

Howard Communications model 460 receiver and Haiti - crafter model S53A receiver. Manuals and schematics needed. S. Selowentchich, 135 CoBax Ave.. Clifton, NJ

07013.

Central Electronics, model 20-A multiphase exciter. Sche- matic and manual. A. McGinnis, WA2DTQ, 55 Patton St.,

Iselin, NJ 08830.

Hammarlund model HQ200 receiver. Operation manual,

schematic and parts list. William A. Unrath, 134 Grove St.,

Ramsey, NJ 07446.

Hewlett Packard model 400A vacuum tube voltmeter. Need manual and schematic. J. O. Dickinson, 1408 Monmouth Ct. W., Richmond, VA 23233.

Dumont type 208-0 oscilloscope. Schematic and operations manual. C. E. McLellan, Box 575, Clarkson, NY 14430.

AN/USM-32 single trace oscilloscope. Schematics, parts list

and service manual. Wayne Mumingham. 2700 Eaton Rap- ids Rd.. Lot 228, Lansing, MI 48910.

Precision Apparatus Co, Inc. oscillograph series ES -500.

Need schematic and parts list. Sgt. M. E. Rudd, P.S.C., Box

944, MacDill A.F.B., FL 33608.

American Trading Corp., model 8P vhf/uhf monitor receiver. Schematic and manual. A. L. Oliveira, 94 Polomska St., New Bedford, MA 02740.

Concertone series 90 reel recorder. Operation and shop manual. Dumont model 304 -HR oscilloscope. Need operation manual. Kent Waterman, 3833 20th St., San Francisco, CA 94114.

Phllco model 39-85 radio. Schematic and parts list. Tim

Floyd, 3113 N. Norfolk St., Indianapolis, IN 46224.

Mallory model 12V multivlbrator, Need several for GE ra-

dios. Chuck O'Connor, Box 264, Santa Clara, CA 95052.

E.C.I. Courier 50 FM transceiver. Schematic, parts list and

operating manual. W. Person, 135 Roe St., Staten Island,

NY 10310.

Zenith model G500 6 -band transoceanic receiver chassis 5640. Need schematic and any other information. 0. J.

Kluth. 503 E. Skillman Ave., St. Paul, MN 55117.

Dumont osdllograph type 304H. Need instructions, service manual and gralicute. Richard W. Schramke, RD 5, Box 164, Tyrone, PA 16686.

Code -A -Phone model 700 telephone answering machine. Schematic and service manual. W. C. Hoar, 1273 N.W. 9th

St., Homestead, FL 33030.

Solo Symphonic model 1113 record player. Schematic and

Parts list. Robert A. Yetman, Rl. 1, Box 200R, Doniphan, MO

63935.

Scott model 222C stereo amplifier. Schematic and repair

manual. E. C. Ozag, 823 N. Marion, Oak Park. IL 60302.

U. S. Navy model R-4A/ARR-2 aircraft communications re-

ceiver. Jason Spitzer, 437 Carrillo St., Santa Rosa. CA

95401.

Concord model F-140 stereo cassette recorder. Parts list and schematic. Roy P. Swauger, 104 Valley Drive, Bridge-

port, WV 26330.

Dumont model 304H oscilloscope and model 264A voltage calibrator. Need operations manual. schematic or any other information. John R. Stephenson, 6057 Pemecia St., Jack- sonville, FL 32210.

Hallicrafters modal S38 receiver. Need operating instructions and manual. C. E. McLellan, Box 575, Clarkson. NY

14430.

Heathklt model V -7A VTVM. Schematics and operating in-

structions. Knight model KG -680 capacitor checker. Scott Silva, Box 2394, Orcutt, CA 93454.

Supro model 36698 guitar amplifier. Schematic and parts list. W. D. Chupp, 806 "F" Lane, Elkhart, IN 46514.

Concertone model 302-D stereo 4 track tape deck. Need

schematic, parts list and repair manual. Bill Szarek, 6515 Spring Rose, San Antonio, TX 78249.

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METAL FILM RESISTORS cud,, 445 VALUES IN STOCK - 10 ohm to 475K ohm

t 1% 1/4 WATT CRA th (RN60)

TEMP. COEF. t 50 PPM/° C

Mill Orr ,p:Oi Pni ict ,nk7 le. v.l ek. it let, kit. i

vee ..l gel ve.., i.e1 e,..,.1 1-e0 .7iS,. .70e 7.75/75 10. 0., -iii ,'Soe. 1.10/75 7.50/IW

p, .0 ,a e. 2.00/75 475 Poo

CARBON FILM RESISTORS ifff

;S%p V4, 47 K kf. ,: QTY. PRIG PRICO vRICf

n a, h1 SiI 10

5

m, loo

p+.aloe, pus .m .,toe,

10 5.10 e. 10-100 5.10 e. 5.05 r4

100.1000 5.04 ea 51.60/100

1000- 52.50/100

CERAMIC CAPACITORS 1pf Z2pf 56p1 120pf 270pí 820pí .00470 .030uí 5pí 7p1 68pí 150pí 79001 .001uí . 010 .05our 7pf k3pf 8201 180pr 470pf .001501 .Olson .ill lOpf 970 IOOpr 22op1 60001 .503uí .022,8

1pf-.6500 .iur 1.9 per value 5.10 1.15 10-99 .06 .10 700- .05 .38

POLYESTER FILM CAPACITORS

1-9 10-99 100- 1-9 10-99 100-

.001,/110V .12 .09 .06 .022u/100V .13 .08 .07

.00370/-O0P .12 .09 .06 .023u/50V .13 .08 .07 .0042u/900V .12 .09 .06 .033,11006 .15 .09 .08 .01,11008 .12 .09 .06 .047u/100V .19 .16 .12 .015,01006 .12 .09 .06 .1u/100V .24 .20 .15 .0180/1008 .12 .09 .06 .22u/100V .33 .20 .17 .020/506 .13 .08 .07 .47,/1008 .50 .30 .25

TANTALUM CAPACITORS 1.9 10- 1-9 10- 1-9 10-

.220351 .25 .20 6.8u/6V .30 .25 220/16V .45 .40

.33,/351 .25 .20 6.8,/168 .30 .25 33u/10V .55 .50 10/356 .25 .20 6.80/506 .35 .30 47u/6V .55 .50 2.2,/200 .28 .23 10u/16V .35 .30 47,/208 .65 .55 2.2,/364 .30 .25 100/236 .38 .33 56u/60 .75 .65 3.30/360 .35 .30 15u/6.3V .38 .33 100u/20V 1.45 4.70/161 .30 .25 15u/20V .45 .40

write for info on kits of all above products

rm,,, ,,,,,,.rr,p 0w,a.nro. 3.11e.r h0 ü WO ONO. P.,uo 5.i 1.iiGRi 01.k005O OPi r0,xxi, .o0 1ati - 9151 n,a0. ú.0[n S.I.rO 1. 1 .o.r1.4 .L(t3Pr, xl.i+ O.xº 110.00

120- he rp

INTERNATIONAL ELECTRONICS UNLIMITED

225 Broadway, Jackson, Ca. 95642



'SALE,

'eó

IT'S NEW! IT'S EXCITING! POLY PAKS GIANT

"ONE PENNY GETS YOU TWO' *Buy any item on this page and choose 2nd item for only on

K of the same cat. no.

A PENNY MORE GETS YOU TWO

O :6 -SKINNY TRIM POTS. PRECISION, asst. styles, values SO% yield 1 3389) 2.29 12 far 1.30 C 60pcPRECUT, PRETINNED WIRE. various length. and colors 1 1971) 1.19 120/or 1,30 60.191111 RESISTORS, for PC appl., vert, 1/SW, color coded 1 22351 1.29 1201o, 1.30 O {-TRANSISTOR RADIO EARPHONES.* ohms roped 1.2946) 1.29 9, 1,30 O 10.5K POTS. .odio taper, pinntic snap -In mounting 1.51241 1.29 2i0611: 1.30 20.112 MEG DUAL POTS. audio taper. "snap -In" rent , 51251 1.28 2019: 1.30 O 50 1 AMP ZESERS. wide east. of values. untaet.d 1.1964) 129 1001o, 1.30 12 -SCR's a TRIACS, ID AMP, ...t. value.. untested 1 20171 1.29 2419, 1.30 O 3-QUADRACS, 10 AMP. 200% prime, 50.100.200 V. TO -2201 50401 1.29 Sloe 1.30 20 -MINI RECTIFIERS, 119 AMPS. 2511, epoxy, axial (+53741 1.29 4010, 1,30 /0264007 2000V MINI RECTIFIER, .poly case. axial lasd. 1 2383) 1.29 ZOlor 1,30 O 75 -MOLEX CONNECTOR Type M1930-4. make. 14 to 40 pin sockets (.16051 1.29 ISO for 1.30 O 501 FORMERS. .Sat sin. (-3549) 1.29 1001:: 1.30 0 I0-T.V. CHEATER CORD JACKS. ( 5519) 1 29 201or 1.10 O 20.1 AMP 2000 MINI RECTIFIER. 1N4003, CP9.y, axial (' 2379) 1.29 2010, 1.30 0 4.1.50 SILVER OXIDE WATCH BATTERIES. 1-5043) 1.29 41o, 1.30 3 -LCD WATCH READOUTS. 311" digit.. 7 eel, dim 115. I") SO661 1 29 610, 1.]0 O 20 -IC DICE CHI, complete circullrr. beal..irbe (5065) 1.29 4010, 1.10 13 21001(112 MARKER CRYSTALS, specify 104.067, 104.092, or 114.00 KHz le 1/961 1.29 4 ter 1,30 0 12.1.50 LAMP AND SOCKET SET. 200ma,12 style I- 39561 1 29 2419: 2.30 10 -RCA PRONO JACKS, cha..l. mount. Iellon base (. 5219) 1.29 20 for 1.30 O 10 -COAXIAL PIN HEAD LEOS. RED 1 56171 129 2010, 1.10 o 4.S -DIGIT 7 -SEGMENT RLADOUTS.In flat pall case 1.5616) 1.29 Olor 1.30 O 4.15" BLOCK TRIM POTS. SK 12536) 1.29 a for 1.30 U I "FOTO-FET" N CHANNEL, Cryse.lonic2s 1.Se.led Ellsot Trensieto,S. 1.11631 1.29 210, 1.30 O 1.VOLTAGE REGULATOR, TO202 case, 1211 600MA 1.19001 1.29 210, 1.30 O 1.3 DIGITS ON A DIP. LED. red. DL33 I 11071 1 29 210, 1.30 Cl 3-MMS26226 DYNAMIC RAM. specify type 1 3459) 1.29 610, 1.30 O 10 211711 NIGH SPEED SWITCHING TRANSISTORS. TOILnon 1 3374) 1.29 2010, 1.30 0 2-15W HI POWER TRANSISTORS, 2200.npn. T0661 2797) 1.29 410,1.30 C 3 24 PIN IC SOCKETS( 2161) 2.29 6for 1.30 O I'MM5312 DIGITAL CLOCK CHIP. 100%), 1525) 1.29 2 for 1.30 O 2 MMS72S 4 FUNCTION CALCULATOR CHIP. 200% 12036) 1 29 410. 1.30 O 1.665202 ERASABLE PROM. 100%1. 3459) 1.29 29,1.30 CI 3,20 AMP 2511 BRIDGE RECT. comb style 1+2447) 1.29 6110, 2,10 0 10-2113565 RF TRANSISTORS, 70106, 2119133 l 3372 121 2010, 1.30 6 -LINEAR SWITCHING TRANSISTORS. 2042905. pop. TOS 13375) 1.29 1210,1.30 S02 AMP CYLINDRICAL RECT. up to 111.u -test 1-40061 129 10010,1.30 O 6 -OPEN -FACE READOUTS. LED. red, some e.g. mllsine coolly duels 1 33521 1.29 1210, 1.30 C 10-202222 (or.eu.v.), TO -1S m.t.lc see l 1992) 121 :

1.29 201o2019,1.301,30

1.29 1610, 1.30 1 29 301901.30 C 10.2N3704 T092 TRANSISTORS ! 3490) 1.21 2010,1.30 I' A2115001 TRANSISTORS STUD) 28001 1.20 210,1.30 0 3 MICROPROCESSOR/SUPPORT CHIPS, asst. 24065750.90 serfs, 24-29 pin 1.963971' 1.29 610, 1.10

B CLOCK/CALCULATOR CHIPS, .W.11115370 75. 5737 etc. 1.5638A' 1.29 1210, 2.30 O 23 DEL FAIRCHILD IC's, gales and flip flops. Dip, 100% (.3709) 1.28 50 tor 2.30 0 2.24 VOLT SO MIL. TRANSFORMER, 1159 input. :pan tram:, l" x 1" 2 3/4. 1.5631). 1.29 2for 1.30 10-2113704 TRANSISTORS, silicon. 70.92 ca....1.-300,100%1.5625) 1.29 2019:1.30 /0-263705 TRANSISTORS. lllcon, TO.92 case. 01. -ISO, 100%1.5626) 1.29 2010, 1.30 1003302/ TRANSISTORS. low po..r,.11lcon, hl. -60. TO -921.5627) 1.29 2010,1.30 1 ALLEN BRADLEY POT, 10K, 2.1 4 watt.. type -1, 2" c'A" .haft (.1748) 1.29 210, 1.30 SO ASST. RED LEOS. 20% or better, nrloue styl.. and types (.5624) 1.29 100 for 1.30 10 OE. POWER TAB TRANSISTORS, D40111. N2, same NS, T0-220).5629) 2.29 2019:2.30 O 2. 4" BLOCK TRIM POTS, 200K 12535) 1.28 410, 1.30 1.12VDC SMIL REED RELAY. .p.0 0.0, 2200 bhm., 7/0"S/16".5/16"(.5315) 1.29 2for 1.30 50 TEMP. COEFFICIENT VOLTAGE REF. DIODES, ssat. volt, +50% (.5647) 1.29 100 for 1.30 000LM.31101C's,2watt., dip, SOS. yield, U -twat 1.1975) 1.29 20 for 1.30 O SO RED BLOCK DISC CAPS. assorted values. 50% material 1.16981 1.29 100 for 1.30

SO SHOCKLEY DIODES, most popular switching diode, hobby & untested (.107261) 1.29 100 tot 1.30 0 6 OPTO -COUPLER. 10000 Isol.tlon, hobby material, U-le.l I.2629Á) 1.29 12 for 1.30 4 CHERRY MICRO SWITCH, 1251/AC,ISA,M.C. type E-13. some terminal. 1.55251. 1.29 8for 1.30 0 9 SPST PUSHBUTTON MOMENTARIES, rt. angle, pc mt, on.on' 1.5635) 1.29 1010, 1.30 O 25 TEL's, with 7400'., U -test, dlps ('2415ÁI 1.29 SOlor 1,30

10 DATA ENTRY SWITCHES, SPST, I amp, norm open 125113).5321) 17 f -TRANSISTOR RADIO EARPHONES. I1 ohms Upped (a 29461. 17 15 FLUORESCENT OVERFLOW READOUT TUBES, ta/leads I. 32001

T7Re 0 067401 5.11 0 567402 .10 0 467403 .I5 0 567405 ,21 O 557404 29 0 557407 ,29

067409

21 5147410 511 .28 567413 ,40 0 567410 .28 O 567430 .1f O 967423 .2/ 0 5117420 ,29

O 107437 25 0 167437 .28 0 567430 .28 O 5117440 1/ 0 5117443 0f

1,000,000 TTL IC "A PENNY MORE GETS YOU TWO" SALE Ws our special penny IC JAMBOREE for our valued customers everywhere! Order by Cat. Ne. 12CU1N1 a Type No, 2 FOR

{.19 .10 .19 .22 .30 .30 .22 .ill .26 .41 .20 .20 .30 .30 .30 .24 .29 .20 .70

TYp. O 367444 O 5117480 0 867481 O 3117453 0 8117484

SN74SS O 567440 0 807464 0 567445 0 5N7470 O 8117491 0 067414 0 1117498

10174111 0 5614911

6N74207 0 /074109 O 5074114 0 5674121 O 8074123

.30 .59 .49 .69 61

.33 .34 .49 ,g0 .20 .20 .35 ,30 .ee 40

2 FOR Type SALE .89 .40 O 167473 .20 .21 O 967474 .20 .21 O 557440 .20 .21 0 557442 .21 .22

O 567443 .10 .20 O 567445 .21 .22 0 557444 .10 .20 O 56741110 11 10

RIBBON CABLE AT THIN PRICES Cond Sale 21or Ultra Hatt 0 10 1D 11 51.911 2011 91.99 28 A W G 0 14' / ft 1.98 16 11 1.99 0 20 S ft 1.90 10 11 1.99 0 25 4 11 1.98 0 ft 1.99 O 26 4 11 1.98 0 ft 1.99 0 34 3 11 1.98 6 ft 1.99 0 36 311 1.98 1311 1.99 0 40 2 11 1.98 4 ft 1.99 0 SO 2 11 1.98 4 11 1.99 0 60 111 1.98 21t 1.99

FREE! FREE! Buy 82000 Worth Choose Any Two

*139 Items Free

Order by Cat. No. 3939 and

nductors

'color coded.

SALE 2 loe 30 .31 .35 .30 30 .92 .89 .70 .69 .70 .09 .90 .79 .90 49 70

.31 0 51174102 .79 .40 .31 13 9674192 .15 ,14 70

0 9074193 ,09 .M .70 01674194 .N ,40 .14 0 9/174195 ,8/ ,70 0 9674197 .49 .10 O 5674199 1.40 1.40 0 1674200 4,08 4.14 0 9674294 3.99 3.14 O 91174299 3.99 3.11 91174290 1.45 1,40

10 AMP - POWER TAISI 1730 SCR'S

1444. TRIACS 1950' 0UADRACS

PRY Sala 2 for SO 9 ,6S S .70 100 .14 .09 200 1.19 1.20 4000 1.39 1

1N4000 Epoxy Rectifiers Cat. No. Type 2377 164001 23711 1114002 2379 1114003 2300 1114004 23.1 1114005 2302 1114006 23113 1114007

Volt. 5.1 lc SALE! 50 10 tor 6 .75 20 for 5 .76

100 10 for .55 20 for 46 200 10 for .95 20 for .96 400 1019: 1,19 20 tor 2.20 600 IO for 1.39 20 tor 1.40 400 101e, 1.49 20 for 1.50

1000 10 for 1.59 20 for 1.60

enny!

O 30 RADIO AND TV KNOBS, asst style., size. 1"52271 129 00ío, 1.30 O 60 TUBULAR CAPACITORS. .0.t volt. and sires 1 B219) 1.29 120 for 1.30 O SSLOW NOISE RESISTORS W, SSW. KIFI, etc 1-220) 1.29 1120:11+:1,30 50POWER RESISTORS. 3,5,7., axial, pop sizes (12201 1.29 1001:, 1,30 O S25 SURPRISE. all Find. of part. in. pak 1e 1294) 1.29 2 to, 1.30 012 PANEL SWITCHES, rotary, elide, toggle, etc 1.5295) 2.29 2419: 1.30 O 60 COILS AND CHOKES, rl, parasitic, II, etc 1.0297) 1.29 1201o, 1,30 O 60 TERMINAL STRIPS. up to 4.old.r lug. 4 8334) 1 29 I IOlor 1.30 60 PRECISION RESISTORS, NW, 11,.cial 1.0363) 1,29 1301::1.70 O 50 MICA CAPACITORS. ..I values 153731 1.29 300 for 1.30 O 10 SETS RCA PLUGS AND JACKS, chono(.04021 1.29 201or 1.30 O 60 DISC CAPACITORS, aael ealues long lead. (8437) 1.29 1201:: 1.30 C 20 TRANSISTOR ELECTRO'S, east up and al (.8453) 1.29 4019: 1.30 75 HALF WATTER S. resistor., color coded, asst 3.0454) 1.39 1.30 O 35 SILVER MICAS. red back., exist, not. (8455( 1.29 1,30 0 6.50 AMP HECT. ae.t rolls up to 25,.tud L717( 1.29 1.30 0.100 GERMANIUM DIODES, axial leads, o.0.2í.L642) 1.29 3001::1.70 0 100.STABISTORS, Regulator. sensing and computer. Asiel, excellent yield 1.3140) 1.29 200 for 1.30 O 100 PRINTED CIRCUIT V. WATT RESISTORS. n.11,11060) 1.29 20010, 1.30 O 12 TRANSISTOR SOCKETS. .1 non and ono type. (6651) 1.29 2410, 1.30 O 503 AMP SILICON RECTIFIERS. axial, net V 1.6665) 1.29 100 for 1.30 O SO POLYSTYRENE CAPS, plastic coated. pass. 1°U10521 1,29 IOO Ior 1.30 O IO NE -2 bulb., for 1lOV.c project., hobby, etc ('U1222) 1.29 2019:1.30 O 10 PROXIMITY REED SWITCHES. 0125{) 1.29 2010, 1.30 620915 UHF TO-IB TRANSISTORS 1.1.114231 1.29 12 for 1.30 Cl 30 MOLEX CONNECTORS. nylon, asst. sl..s 1. 96421 1.29 GOtor 1.30 O 50 -MINI BLOCK CAPACITORS, Erie. red square discs. Asst. values.4'16982 129 100 for 1.30 0 6 -CALCULATOR AC ADAPTOR JACK, standard threads 3 terminals. (2316) 1.29 1219: 1.30 O SO ONE AMP ZENER DIODES, list, axial, u test 1.01964) 1.29 1001:71.30 O S -PÁ.263 THREE WATT PC BOARDS, for amps (.12013) 1.29 1019: 1.30 O 5 MINI MOTORS. 1H Vdc. for many hobby proj ).U2SSl) - - 1.29 1010: 1.30 O SO1144000 RECTIFIERS...0t 500000.0 1..1)62594) 1.29 10010:1.30 O IS PRINTED CIRCUIT BOARDS. a..t sizes. hobby( U2010) 1.29 30110, 1,30 O 2 MERCURY SWITCHES, silent touch. SPST ('62023) 1.29 4to, 1.30 C 6 ITS A SNAP, 9 VDC BAT clip, red n black lead l 02082) 1.29 1219 1.30 17 8 1400 VOLT "RED SALL" RECTIFIERS. aí1.1 1 AMP 1 625901 1.29 1610, 1.30 020/114148 SWITCHING DIODES. 4 nasc. axial 1-U3000) 1.29 40 for 1.30 O3-10 AMP GUAORACS,w/trigger diode up 6000 163620) 1.29 51071.30 O 5 MICRO SWITCHES. pu.h. cell types 1'U30I1) 1.29 10 for 1.30 O 40 SQUARE DISC STYLE CHOKES. color coded (.63203) 1.29 »1012.30 O 30 TRANSISTORS T0922114400sarJe.. u test 1+13291 1.29 Sofa: 1.30 O 6.TRRESISTORS TRANSFORMERS..u/to. Inter. etc mini 1.63295/ 1.29 12 tor 1.30 O IS PRINTED CRT TRIMMER POTS. asst values, etc 1.133461 1.29 30 for 1.30 O 2011 CABLE, 1 coed shielded, 1.24. for phono (.63653) 1.29 4018 1.30 O 10-PNP 30 WATT T0.3 TRANSISTORS, hobby 4.63772) 1.29 201ar 1.30 O 50 TUBE SOCKETS, 4, 5.6.7 pin tubes, +sat 1.U31139 ía29 100 3:: 1.30 0 1.20 AMP POWER TAS QUADRAC, 200 PRY, 70220. 2/trigger 1 15901 1.29 210, 1.30 10 -BULLET RECTIFIERS, 2.5 amp. 2000, axial 1.041 1.29 20 for 1.30 0 6 -READOUTS. MAN 3, common cath. LED, the clew. RED 1.3338) 1.29 1219: 1.30 0 LEEDS, asst. sloes and shape.. red, . yellow. amber 1.38691 1.29 16 for 1.30 3 PHOTO FLASH ELECTRO. CAP, 600 MF 360V 4"3097) 1.29 21or 1.10 0 2 -CIRCUIT BREAKERS. glass sealed. acIsl, rated . I .rep 1.3905) 1.29 41or 1.30 MICRO MINI TOGGLE. SPST, 2 pot, on -011,125V n 3 amps (.39361 1.29 2 foe 1.30 O 5-C11 CRYSTALS, orig. used w/.ynthealter, a.et. lest, HC -18/U holder (-'50511 1.29 10 for 1.30 O 4 -PUSH BUTTON, SPST, PANEL. N.C. 1290 " I A 3.52191 1.29 4 for 1.30 0 10 -INSTRUMENT KNOBS, best. style. and color.. 'A" shaft (.5121) 2.29 2010, 1.30 0 4 -TAPE HEADS, 14111 type. 1+ 5182) 1.18 {for 3,30 0 S -TANTALUM ELECTROS, TEARDROP style, 2.201 " 2SY (5205) 1.29 10119: 1.30 02.INLINE FUSE HOLDERS. completew/S amp tuse 1.5213) 1,29 410,1.30 0 30-4" CABLE TIES. non -slip white plastic 1'5217) 1.29 6010, 1,30 O 30p, -NEAT SHRINK, ...t. she.. SO% shrinkage 1.5248) 1 29 SO lo, 1,30 O 20-TOROIDS, some with coils 4.5431) 1 39 4019: 1,30 O 10 159 ZENERS, 40Omw, asl.I. Blaas ces. (.5404) 1.29 2019: 1.30 O 2.ALUMINUM HEAT SINKS, for TO -2201+53311 129 41or 1.30 O2-5.10.51, 10W. STUD 2EMER. DO.A .1.1r, 32071 1.29 4far 1.30

POP OPS STARRING {SOoOOPS++ p PENNY MORE GETS YOU TWO

Order by Type No. {ALE 2 FOR

Typo 11 .N O "S4 .3f

.40

O LM703H f0 .30

LM701N 27 40

O 31 19011

UM713N 195 .60 p LM733M

O Lp1741I o 5,137Á1N ],00 0 LM130411 p LM l3fON y49 ? 0 REC1311M 4f N p LM141CM 79 ,70

.6300011 N250 00

SALE 1 TYpe ,49

.50 0 LM300N .4f .36 0 LM300M ,26 LM30lll .2S

.]0 O 0430 04 LM306V .61 .N

¿M41/ f.00

*V :M 1.00 0 LM310-611 f .60

0 LM32zM .Sf ,50 0 LM322N 151 .N 1.00

170 LM.24V .M 1.00 1,00

, p LM3401.1SV .1H l,N 7f

pLM37711 L.61 .M p LM360N 1A/ /.50 0 ME631N .30

O NE532N 1.25 1.24

0 MES56N H NE65aN l.M

NE84yM ,40 .w

1. 10 WATT STEREO

AMPLIFIERS! PA, 1.11, mobu., 02V 1.53241

6Y 2 for 0.119

LED WATCH GUTS s Q 2for 1 a9 51.96

25 AMP BRIDGE RECTIFIERS

Order No. 2273 voltage

IV 2 FOR SALE 0 25 1.26 1.21 0 80 1.11 1.95 0 100 2.2N 2.28 O 200 2.14 2.95 O 400 3.51 3.50 O 000 4.26 4.28 O 000 4.94 4.15

LASER DIODES

$8.88 LMBOH 1.29 .>o

Y 889 0 7su4b1 ,2f 2 for 0 7{453 ,49 N .

O 71M11 .40 .70 (3 75492 .N .79 c3 71415 :

1.00 . 3501 o A253 O UM0684

F 'Iy.eround." Do they work? Who knowel A rots:. di.ltal . a.hnlelen . Th complete Set. ere there. With black asbe end le.thrH band. S lunctlon: HOURS. MINUTES. SECONDS. MONTH. A DATE, Sorry, n9 p .. Cat, No. 5267 Wt 4or:

HOW TO ORDER When 9rdsnlng. .1..ys use '

catalog numb.:, type no., the of M. mavein. you .

ordd.rins from and the month

9-b POL

PAKS®

i DOD'. MAY P.O. BOX 942-E4 BE PHONED! SO. LYNNFIELD, MA

01940 Terms: Add Pobtage Rated: Net 30

o Phone: (617) 245-3828 Retell: 16.18 Del Carmine Si.

MIN/MUM ORDER: $8 Wakefield, MA i Jf

St YOUR C OIC ` 0 91.29 1p 12 for 51.3Q

Ord./ bya W No. IT» MICRO TOPHAT RED 2942 MCD YELLOW STURDY 2795 MICRO SINGLE PIN RED 27 ] JUMB Amber 2115 JUMBO RED 213 O OREEN

MICRO 2 f RED 279060

MICR 1ÚM60 RED CLEAR

-11111 .. y



* * * * * . * r * * z; p{

5i-8OO-346-5144 §»..' 0 MN., AK., HI. RESIDENTS 218-681-6674

DON'T FOR T OUR I.C.'s RESISTORS TRANSISTORS CAPACITOR S DIODES I.C_ SOCKETS & PINS SWITCHES

' DISCOUNTS WHEN COMPARING PRICES CLOCK MODULIES OPTOELECTRONICS BREAD GOADING d TESTING DEVICES DRAFTING SUPPLIES

DATA BOOKS HEAT SINKS WIRE TOOLS . , . AND MORE . , . WRITE FOR FREE CATALOG

r'{ INTEGRATED CIRCUITSI.C. Socket Prices NE MA1023 by I The "NIBBLER" ANASONICFLKTROLTTICA.aTS

U on Louse 1 r754S3 1 NATIONAL ' Rm1 LIAOS .B:T,TáT L3, I,:,,

74op: }i ÍaSOD x.(roN -s 7Mu ú A MICROCOMPUTER rElvs I 11,, la 1 70 loo

1101 U 74150 98011N 35 )540 el

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741n It 131503 28 .111Nq 75i9

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»pa V 741504 )9 71 ION 35 rH 1 100

1 C- T1 ] J SOv ) 1 O1 es3 .11 190

)b5 ]I 141505 20 '4046 qp 1101 In ra SOCKÉTS % yd; .]]SV .. 2 I.Oi é s1 n :+o I, e)

7406 75 74150e » ncmN 7s Ma148N au - - -.- MOCK MODULE s ; 9.';7] .v sov .0 I w .oe m Le Hm

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7414 89 14(83- 1.30 Fg741 J6 ,6s1 0nS0Itl«Tr le __.

7414 25 1.15x .Po 11085N IlB MJOIAN .. 10 ST leP.Solónrta6 le - ; /'' - 1J16V 11 Lle W.XI I,N 1Ol 14V ,n 741575 .18 Ill 00 M107s 64.n51 70PnSolderrnn .}0 _

IJ7sV . U 110 9.48 .» 1 1 IS B1

)420 11 7 15n Po a(0or4 Po MYaN 100

]a 35V 10 1 e1 la 10 .n ].}, e 60 . 1481 15

4:1 11

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ANNOUNCING OUR SPRING SALE with big $$ savings for you on BapRIcisioN

Dual -Trace 10 MHz Triggered 5" Scope Reg. $655.00 Our Price $555.95

MODEL

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MODEL

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tion Tests

diodes, SCR's, FET's, and Darlingtons


PRIME TTL & CMOS AT LOWEST PRICES 7480 ....0.31 74181 ...1.75 741542 ..0.60 7410192 .0.90 74578 ...0.58 74C48 ...0.96 4007 ....0.16 4086 ....0.64 74xx TTL 7482 ....0.50 74182 ...0.75 741047 .. 0.75 7415193 .0.90 745112 ..0.58 74473 ... 0.62 4008 ....0.74 4089 ....2.75

m VOLUME 'DISCOUNT 'SCHEDULE 7483 ....0.54 74184 ...1.75 741.048 ..0.72 7415194 .0.85 745113 ..0.58 74474 ...0.48 4009 ....0.35 4093 ....1.55 Merchandise Total Discount 7400 ...50.14 7485 ....0.80 74185 ...1.75 741551 ..0.25 7415195 .0.50 745114 ..0.58 74476 ... 0.68 4010 ....0.35 4099 ....2.10 5 0.00-S 9.99 NET 7401 ....0.15 7486 ....0.27 74188 ...2.80 741554 ..0.25 7415196 .0.80 745132 -.0.75 74C83 ...1.28 4011 ....0.16 4104 ....2.40 5 70.00-5 24.99 LESS 5% 7402 .... 0.15 7489 .... 1.75 74190 ...0.95 741055 ..0.25 74L8197 .0.80 740133 ..0.38 74C85 ... 1.20 4012 ....0.16 4503 ....0.98 5 25.00-S 99.99 LESS 10% 7403 .... 0.15 7490 .... 0.40 74191 ... 0.95 741573 .. 0.38 7415221 . 1.05 740134 .. 0.38 74C86 ... 0.40 4013 ....0.31 4507 .... 0.37 $ 100.00 $499.99 LESS 15% 7404

7405 ....0.16 7491 ....0.51

7492 74192 ...0.80 74193 0.80

741074 ..0.35 741576 .. 0.37

7410251 .0.80 7415253.0.80

74$135 ..0.49 745138

74089 ...3.95 74490 0.92

4014 -4015

....0.73 4510 4511

....0.45 $ 500.00-5999.99 LESS 20% 7406

....0.16 ....0.24

....0.40 7493 ....0.40

... 74194 ...0.80 741578 ..0.36 7410257 .0.70

..0.77 740139 ..1.50

... 74493 ... 0.92 4016

....0.73

....0.28 4512 ....0.93 ....0.64 51000 00 and Up LESS 25%

7407 ....0.24 7494 ....0.60 74195 ...0.49 741083 ..0.75 7415258 .0.70 740140 ..0.47 74C95 ...1.04 4017 ....0.78 4516 ....0.76 7408 .... 0.17 7495 .... 0.60 74196 ... 0.73 741085 .. 1.30 74LS259.1.60 745151 ..1.25 744107 .. 0.68 4018 ....0.78 4518 .... 0.76 STANDARDSHI]7PINGCH/RGES 7409 ....0.17 7496 ....0.60 74197 ...0.73 741586..0.36 7415260 .0.34 740153 ..2.10 744151 ,.1.78 4019 ....0.21 4519 ....0.62 II your Merchandise Total is between: 7410 ....0.15 7497 ....2.45 74198 ... 1.30 741590 ..0.50 74L5266 .0.26 740157 ..0.75 74C154 ..2.90 4020 ....0.83 4520 ....0.68 $ 000-5 4.99 add 52.00 7411 ....0.18 74107 ...5.29 74199 ...1.35 741092 ..0.50 7415279 .0.52 745158 ..1.25 744157 ..1.78 4021 ....0.83 4527 ....1.48 $ 5.00-524.99 add 51.00 7412 ....0.20 74109 ...0.32 74251 ...1.00 741093 .-0.50 7415283 .0.72 745174 ..1.50 740160 ..1.08 4022 ....0.83 4528 ....0.86 $ 25.00-549.99 add S0.75 7413 ....0.25 74121 ...0.29 74279 ...0.49 741$95 ..0.85 7415290 .0.60 740175 ..1.45 744161 ..1.08 4023 ....0.16 4532 ....0.86 s s0.00-599.99 add $0 50 7414 7416

....0.55

....0.22 74122 ...0.35 74123 ...0.39

74283 ...1.00 74290 ...0.59

7415107 .0.35 7415109 .0.35

7415295.0.90 7415298 .0.90

745189 ..2.75 740194 ..1.75

740162 ..1.08 744163 ..1.08

4024 4025

....0.66

....0.16 4539 4555

....1.10

....0.67 5100 and Up NO CHARGE 7417 ....0.22 74125 ...0.37 74293 ...0.57 7410112 .0.35 7415365 .0.52 740200 ..3.25 740164 ,.1.08 4027 ....0.37 4556 ....0.88 7420 ....0.15 74126 ...0.38 74298 ...0.92 7415113 .0.35 7415366 .0.52 745206 ..3.75 740165 ..1.08 4028 ....0.73 4582 ....0.88 The above charges include shipping via 7421 .... 0.17 74132 ... 0.65 74365 ... 0.62 7415114 . 0.35 7415367 . 0.52 745253 .. 0.95 740173 .. 1.16 4029 ....0.98 4584 ....0.74 First Class Mail or UPS (your choice), 7423 ..-.0.25 74141 ...0.70 74366 ...0.62 7415123 .0.90 7410368 .0.52 744257 ..1.15 74C174 ..1.08 4030 ....0.21 4702 ....7.10 and insurance on all domestic 7425 ....0.25 74145 ...0.65 74367 ...0.62 7415125 .0.46 7415386 .0.36 740258 ..1.15 740175 ..1.04 4031 ....2.97 4703 ....8.25 shipments. 7426 7427

....0.22

....0.19 74147 ...1.50 74148 ...1.15

74368 ...0.62 7415126.0.46 7415132 .0.72

7415390.1.65 7410393 .1.35

740280 .. 2.25 745287 ..3.20

744192 .. 1.30

744193 .. 1.30 4034

4035 ....2.75 ....0.84

4704 4705

....7.38 ....9.25 SPECIAL SHIPPING CHARGES . -

7430 ....0.15 74150 ...0.79 74LSxx TTL 7410133.0.34 7415490 .1.10 74S289 ..3.55 740195 ..1.10 4040 ....0.86 4706 ....9.75 COD $1.00 -additional 7432 ....0.23 74151 ...0.59 7415136.0.35 7415670.2.29 745300 ..1.60 744200 .. 7.50 4041 ....0.64 4707 ....9.25 UPS Blue 82.00 -additional 7437 ....0.21 74152 ...0.59 741500 .S0.21 7415138 .0.70 745305 ..1.90 74C221 ..1.38 4042 ....0.64 4708 ...14.35 Postal Insurance -additional 7438 7439

....0.21 ....0.25

74153 ...0.60 74154 ...0.95

741.001 ..0.27 741502 ..0.21

7415139 .0.70 7415151 .0.65

745xx TTL 740310 ..2.85 745312 ..1.05

740901 ..0.48 74C902 ..0.48

4043 4044

....0.62 ,...0.62

4710 4720

....6.40 ....6.95

51.00 Special Delivery 51.25 -additional

74500 ..50.35 7440 ....0.15 74155 ...0.65 741003 .. 0.21 7410152.0.65 745313 ..1.55 740903..0.48 4046 ....1.35 4721 ...31.35 7441 ....0.70 74156 ...0.65 741504 ..0.24 7415153 .0.66 74502 .-.0.35 740316 ..2.80 744904 ..0.48 4047 ....145 4723 ..... 0.93 7442 ....0.38 74157 ...0.59 741005 .. 0.29 7410154.1.00 74503 ...0.35 745341 ..4.10 74C905 ..6.00 4048 ....0.95 4724 ....1.29 7443 ....0.55 74158 ...0.59 741008 .. 0.23 741$155.0.62 74504'...0.36 74S342 ..1.20 744906 .. 0.48 4049 ....0.33 4725 ....1.29 INTERNATIONAL 7444 ....0.55 74160 ...0.79 741509 ..0.23 741S156 .0.62 74505 ...0.36 745343 ..4.95 74C907 ..0.48 4050 ....0.33 40014 ...0.72 " 7445 7446

....0.55

....0.62 74161 ...0.79 74162 ...0.79

741010 .. 0.21

741611 ..0.21 741$157.0.62 7410158 .0.70

74508 ...0.38 74009 ...0.38

745346 ..1.25 745362 ..2.15

744908 .. 0.96 744909 ..1.78

4051

4052 ....0.89 ....0.89

40085 40097

...1.47

...0.54 COMPONENTS MIMI 7447 ....0.57 74163 ...0.79 741012 .. 0.27 7410160 .0.82 74510 ...0.35 74S387 ..4.70 744910 .. 6.00 4053 :...0.89 40098 ...0.54 7448 -...0.60 74164 ...0.79 741513 ..0.40 741.0161 .0.82 74011 ...0.38 74C914 ..0.90 4060 ....140 40106 ...C.90 CORPORATION 7450 ....0.15 74165 ...0.90 741014 .. 0.85 7410162 .0.82 74515 ...0.38 74Cxx TTL 740918 ..1.16 4066 ....0.54 40160 ...1.08 ' 7451 ....0.15 74166 ...0.95 741S15 ..0.26 7415163 .0.82 74520 ...0.35 740925 ..7.80 4068 ....0.34 40161 ...1.08 P. O. BOX 1837

74400 .. 5024 7453 ....0.15 74167 ...3.20 741020 .. 0.23 7415164 .0.98 74522 ...0.36 740926 ..7.80 4069 ....0.26 40162 ...1.08 COLUMBIA, MO 65201 7454 7459

....0.15 74170 ...1.85 74173

741521 ..0.23 741522

7415168 .0.83 7410169

74S30 ...0.27 74532

74CO2 ...0.24 74404

744927 ..7.80 740928..7.80

4070 4071

....0.40 40163 40174

-..1.08 PHONE: (314) 474-9485 7460

....0.15

....0.15 ...1.10

74174 ...0.85 ..0.23

741026 ..0.31 .0.83

7415170 .1.60 ...0.50

74540 ...0.35 ...0.26

74008 ...0.25 4073 ....0.19 ...-0.21

...1.08

7470 ....0.27 74175 ...0.75 741027 ..0.26 7415173 .1.00 74551 ...0.17 74C10 ...0.24 4xxx CMOS 4075 ....0.21 7472 ....0.24 74176 ...0.69 741530 ..0.23 74L0174 .0.75 74060 ...0.35 74414 ...0.90 4076 ....1.16 7473 .... 0.24 74177 ... 0.70 741032 .. 0.30 7410175 . 0.79 74564 ... 0.38 74420 ... 0.25 4000 ... S0.16 4077 .... 0.46 7474 ....0.24 74178 ...1.20 741037 .. 0.31 7410181 .2.50 74065 ...0.38 74C30 ...0.24 4001 ....0.16 4078 ....0.35 7475 ....0.45 74179 ...1.20 741038 .. 0.31 7410190 .0.90 74574 ...0.58 74032 ...0.25 4002 ....0.16 4081 ....0.19 7476 ....0.29 74180 ...0.65 741040..0.26 7415191 .0.90 74576 ...0.58 74C42 ...0.94 4006 ....0.85 4085 ....0.64



FAIRCHILD RED LED LAMPS +FL V5057 Medium Size. Clear Case RED EMITTING These are not

retested off -spec units as sold by some of our competition These are factory prime, first quality, new units

10 FOR $119

11111- 50 FOR 5495

"WE BOUGHT 250,000 PCS."

"THE COLOSSUS" FAIRCHILD SUPER JUMBO LED READOUT

A full -80 inch character. The biggest readout we have

ever sold! Super efficient. Compare at up to $2.95 each from others! YOUR CHOICE $149

EA FND 847 Common Anode FND 850 Common Cathode (6 for $6.95)

NATIONAL SEMICONDUCTOR NEW!

CAR CLOCK MODULE - #MA6008 Originally used by HYGAIN to indicate time and

channel on an expensive C.B. Mini size, self

contained module. Not a Kit. Four digits plus

flashing indicator for seconds. Includes MM5369

and 3.58 MHZ crystal for super accurate time base.

With hookup data.

MFGR's CLOSEOUT LIMITED QTY.

$699 each

INCLUDES CRYSTAL TIMEBASE! WORKS ON 12 VDC!

16K DYNAMIC RAM CHIP WORKS IN TRS-80 OR APPLE II

16K X 1 Bits. 16 Pin Package Same as Mostek 4116-4. 250 NS access. 410 NS cycle

time Our best price yet for this state of the art RAM. 32K and 64K RAM boards

using this chip are readily available These are new. fully guaranteed devices by a

major mfg VERY LIMITED STOCK!

"MAGAZINE SPECIAL" - 8 For $79.50

EXPERIMENTER'S CRYSTAL

262. 144KHZ This frequency Is 2

to the 18th power Easily divided

down to any power of 2. and even

to 1HZ New by CTS -Knight A $5

value $1.25 each

4.00 MHZ - $1.75

LAB -BENCH VARIABLE POWER SUPPLY KIT

5 to 20 VDC at 1 AMP. Short circuit protected by current limit. Uses IC

regulator and 10 AMP Power Darlington. Very good regulation and low ripple Kit includes PC Board. all parts, large heatsink and shielded transformer. 50

MV. TYP. Regulation. $ 15.99 KIT

FAIRCHILD PNP 'SUPER TRANSISTOR"

2Nee02 10.92 Plastic Silicon PNP

Driver High Current vCEO.40 HFE-50 to 150 at ISO MA FT -150 MHZ A Super

BEEFED - UP version of Me 253906

8 FOR $1

G.I. FULL WAVE BRIDGE 4 AMP 600 PIV 3/4 In. Square

With Lugs, #LM -1

750 ea. 3 For $2

MOTOROLA POWER TRIAC

TO -220 CASE 15 AMP 400 PRV

SPECIAL: 896 each

5 FOR $3.95

COMPLEMENTARY POWER TRANSISTORS SILICON NPN AND PNP. TO -220 CASE. VCEO - 40V PD - 30 WATTS FOR AUDIO POWER AMPS. ETC.

TIP29 - NPN YOUR CHOICE

TIP30 - PNP 3 FOR $1

FET SALE! 2N4304. Brand New

N Channel. Junction Fet

BVGDO-30V IDSS-15 MA Typ. 1500 uMHOS. TO -18 Plastic

Case Mfg. by Teledyne

6 FOR $1

60 Hz CRYSTAL TIME BASE $4.95 (complete Kill

Uses MM5369 CMOS divider IC with high accuracy 3.579545 MHZ Crystal. Use with all MOS Clock Chips or Modules. Draws only 1.5 MA. All parts, data and PC Board included.

MALLORY COMPUTER GRADE CAPACITOR

30,000 MFD 15 WVDC Small: 3 x 2 Inches

$1.99 ea. 3 For S4.99

RCA HAM & GOVERNMENT BAND CONVERTER KIT

LIMITED STOCK .1

Converts 134 to 150 MHZ FM to listen on regular AM Band. Complete kit. originally designed to sell for about twice our price. Includes P C.

Board. all parts and pre -punched aluminum enclosure! Precision tuning capacitor has coarse and fine control.

CLOSE OUT SPECIAL: 5599 KIT

Digital Research Corporation (OF TEXAS)

P.O. BOX 401247A GARLAND, TEXAS 75040 (214) 271-2461 fl

TERMS: Add 30C postage, we pay balance, Orders under $15 add 756 handling. No C.O.D. We accept Visa, Master - charge, and American Express cards. Tex. Res, add 5% Tax. Foreign orders (except Canada) add 20% P & H. 90 Day Money Back Guarantee on all items.

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METER KITS BUILD A WORKING DPM IN 1/2HOUR WITH

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ICL7106EV ILCDI 529.95 1CL710711E01024.95

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D,l ec tly eM1angeeblar

lntersir5 Universal Counter System EVALUATION KIT

Ballantine Model 1010A Dual Channel/X-Y Scope

A professional oscilloscope - -- to fit

e ' your ' i ' basic

I 'LL.4 ,e,e I needs. -ee;' '!a S695

KIM -1 MICROCOMPUTER

Fully Assembled & Tested

517900 Incluaing - Documentation

1802 SERIES LOS Cerarmc 55 to 125 C

LE- Epoxy -40 t 85 C

PET 2001 PERSONAL COMPUTER

Quite portable, very affordable and un-

believably versatile, the PET computer Islay very well be a lifetime investment.

Model Description

2001 Computer w/8K 2020 PET Printer C2N External Cassette

Pr,cc

S795.00 S695.00 S 99.95

HICKOK LX 303 MU DIGITAL

Compact. Accurate. Dependable. With easyto- eed IS- liquid crystal display for convenient ase

In any kind of hghl. Weigh. Only 8 ounces. Operates up to 200 hrs on a single 9 v011 battery. Nineteen ranges including 200mV to 1000VOC. 100 t0 10 Megohms, 100 and 1000 VAC ranges. snug and IO,nA ranges. Excellent overload Pro-

[pprdinared tease and 5 74 95 color coded panel. li HYBRID AUDIO

POWER AMPLIFIER P/N Power

Matching Transformer

+Ro2LD 519.95 1502LE 51120 SI1070G110Wf 5 6.95 TRIO S 7.90

"11 511030G130WI 519.00 TR30 512.90 ASI.815ocket for above) .95

1822Lo 1400 1812LE 805 SI. 1020G(20W)513.95 TR20 510.90 1924LD 775 1824LE 355 r_

18521.0 a 75 1052LE 190 185310 5.65 19531.E 145 18541.0 11.70 1854 L E 8.30 e56,0 550 1856LE 1 i0 511050G150W1 527.80 TR50 517.90 857LD 565 158

165 LE A.SI101Sockel for above, .95

1858LD 565 aLE 18591.0 ' S 19591.E 1 4. Nola One Transformer can power two audio amplifiers

GRI-ASCII KEYBOARD KIT 5% CARBON FILM iw 753K 606 board S59.95 S1.69 756K Keybeartl 564.95

RESISTORS 701 Enaosure1753 omyIS14.95 i W

702 Enclosure 0,0.1 529.95

SYM-1 The

mom. MICRO ItM1 poular 9'iIe. 0 Computer

w555 Tipmer. I '" - System

1515t1 S269.00 ICM7226EV 55995 51.50 h

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components, PC board and ,nueuclions. $19.95

with RECHARGEABLE PORTABLE 12.7-1.1 v 5.4-W x 7.5'13) BATTERIES & CHARGER

AVAILABLE GPTIONS-usable on both the M5215 and Me MS15

41-140 Leather Carrying Case 545.00 - 41.141 10 to 1 Probe 524.50

,- I i-4-

51.79

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- The Instructor 50

535000 á ` v flood

runand debug achine language(MM.D.

Cn,nnake

from SIGNETICS `- Complete, Ready.To.Use

lilt Microprocessor Learning Package

lutles a vxing t

grams. Housed el ono Compact Dockage.

15 Megahertz PORTABLE MINI -SCOPES

- TRACE MS -215

543500 SINGLE M TRACE S15

531800

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4'14 Y 11,;

Send Check or Money Order 10:

Ar / P.O. Box 2208P, Culver City, CA 90230. California resi dents add 6% sales lax. Minimum Order; 510.00. Add 51.00 10 Cover postage and handling. Most. Charge and

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ARIZONA ANCRONA

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Electron les Cbssif le .c REGULAR CLASSIFIED: COMMERCIAL RATE: For firms or individuals offering commercial products or services, $2.50 per word. Minimum order $37.50. EX- PAND -AD CLASSIFIED RATE: $3.75 per word. Minimum order $56.25. Frequency discount: 5% for 6 months; 10% for 12 months paid in advance. PERSONAL RATE: For individuals with a personal item to buy or sell, $1.50 per word. No minimum! DISPLAY CLASSIFIED: 1" by 1 column (2-114" wide), $300. 2" by 1 column, $600.00. 3" by 1 column, $900.00. Advertiser to supply film positives. For frequency rates, please inquire. GENERAL INFORMATION: Ad copy must be typewritten or clearly printed. Payment must accompany copy except when ads are to be billed on credit cards - American Express, Diners Club, Master Charge, VISA (supply expiration date) - or when ads are placed by accredited advertising agencies. First word in all ads set in caps. All copy subject to publisher's approval. All advertisers using Post Office Boxes in their addresses MUST supply publisher with permanent address and telephone number before ad can be run. Advertisements will not be published which advertise or promote the use of devices for the surreptitious interception of communications. Ads are not acknowledged. They will appear in first issue to go to press after closing date. Closing Date: 1st of the 2nd month preceding cover date (for example, March issue closes January 1st). Send order and remittance to Classified Advertising, POPULAR ELECTRONICS, One Park Avenue, New York, N.Y. 10016. For inquiries, contact Linda Lemberg at (212) 725-3924.

FOR SALE

FREE! Bargain Catalog-I.C.S. LED's, readouts, fiber optics. calculators parts & kits, semiconductors, parts. Poly Paks. Box 942PE, Lynnfield, Mass. 01940.

GOVERNMENT and industrial surplus receivers, transmitters, snooperscopes, electronic parts, Picture Catalog 25 cents. Meshna, Nahant, Mass. 01908.

LOWEST Prices Electronic Parts. Confidential Catalog Free. KNAPP. 4750 96th St N., St. Petersburg, FL 33708.

ELECTRONIC PARTS, semiconductors, kits. FREE FLYER. Large catalog $1.00 deposit. BIGELOW ELECTRONICS, Bluffton, Ohio 45817.

RADIO-T.V. Tubes -36 cents each. Send for free catalog. Cornell, 4213 University. San Diego. Calif. 92105.

AMATEUR SCIENTISTS, Electronics Experimenters. Sci- ence Fair Students ... Construction plans - Complete, including drawings, schematics, parts list with prices and sources ... Robot Man - Psychedelic shows - Lasers - Emotion/Lie Detector - Touch Tone Dial - Quadraphonic Adapter - Transistorized Ignition - Burglar Alarm - Sound Meter ... over 60 items. Send 50 cents coin (no stamps) for complete catalog. Technical Writers Group, Box 5994, Uni- versity Station, Raleigh, N.C. 27650.

SOUND SYNTHESIZER KITS -Surf $14.95. Wind $14.95, Wind Chimes $19.95, Musical Accessories. many more. Catalog free. PAIA Electronics, Box J14359, Oklahoma City, OK 73114.

HEAR POLICE / FIRE Dispatchers! Catalog shows exclusive directories of "confidential" channels, scanners. Send postage stamp. Communications, Box 56 -PE. Commack. N.Y. 11725.

UNSCRAMBLERS: Fits any scanner or monitor, easily adjusts to all scrambled frequencies. Only 4" square $29.95, fully guaranteed. Dealer inquiries welcomed. PDO Elec- tronics, Box 841, North Little Rock, Arkansas 72115.

TELETYPE EQUIPMENT for sale for beginners and experienced computer enthusiast. Teletype machines. parts, supplies. Catalogue $1.00 to: ATLANTIC SALES, 3730 Nautilus Ave., Brooklyn, NY 11224. Tel: (212) 372-0349.

WHOLESALE C.B.. Scanners, Antennas, Catalog 25 cents. Crystals: Special cut. $4.95. Monitor $3.95. Send make, model, frequency. G. Enterprises, Box 461P, Clearfield, UT 84015.

BUILD AND SAVE TELEPHONES. TELEVISION, DETEC- TIVE. BROADCAST Electronics. We sell construction plans with an Engineering Service. Speakerphones. Answering Machines. Carphones. Phonevision. Dialers, Color TV Con- verters, VTR, Games. $25 TV Camera. Electron Microscope, Special Effects Generator, Time Base Corrector, Chrome Key. Engineering Courses in Telephone. Integrated Circuits, Detective Electronics. PLUS MUCH MORE. NEW Super Hobby Catalog PLUS year's subscription to Electronic News Letter. $1.00. Don Britton Enterprises, 6200 Wilshire Blvd, Los Angeles, Calif. 90048.

NAME BRAND Test Equipment. Up to 50% 'discount. Free catalog. Salen Electronics. Box 82. Skokie, Illinois 60076.

SURPLUS COMPONENTS. Communication and test equipment. Illustrated catalog 25 cents. E. French, P.O. Box 249, Aurora. Illinois 60505.

WEATHER MAP RECORDERS: Copy Satellite Photo- graphs, National -Local Weather Maps. Learn How! $1.00. Atlantic Sales, 3730 Nautilus Ave., Brooklyn, N.Y. 11224. Tel: (212) 372-0349.

NAME BRAND TEST EQUIPMENT at discount prices. 72 page catalogue free. Write: Dept. PE, North American Elec- tronics. 1468 West 25th Street, Cleveland, OH 44113.

UNSCRAMBLERS FOR any scanner. Several models available. Free literature. Capri Electronics. 8753T Windom, St. Louis, MO 63114.

UNSCRAMBLER KIT. Tunes all scramble frequencies, may be built-in most scanners, 2-3/4 x 2-1/4 X 1/2. $19.95. Factory built Code -Breaker. $29.95. Free Catalog: KRYSTAL KITS, Box 445, Bentonville, Ark. 72712. (501) 273-5340.

THE GREATCTRONIC THINGS & IDEAS

HUNDREDS OF UNUSUAL PARTS, GADGETS & IDEA ITEMS, UNAVAILABLE IN STORES OR CATALOGS ANYWHERE, Bargain prices on everything! New, ems en every issue! Rush postcard for you, court

1111©11: ELECTRONICS Dept. 035, North Country Shopping Cr,., Plattshhurgh, N.V. 12901.

B&K Test Equipment. Free catalog. Free Shipping. Dinosaur discounts. Spacetron-AS. 948 Prospect, Elmhurst. IL 60126,

SURPLUS ELECTRONICS ATTENTION HOBBYISTS - SEND FOR

YOUR FREE CATALOG Great buys in tape drives, keyboards, power supplies, and r transformers. We also have heat sinks, steel cabinets, I/O terminals, video dos plays, printers, and equipment cases. And 01 course components, fans, wire, and cable. Write now to

130 Northeastern Blvd. Worldwide Electronics Nashua, N.H. 03060

BUILD THE ARTISAN ELECTRONIC ORGAN ... The 20th century successor to the classic pipe organ. Kits feature modular construction, with logic controlled stops and RAM Pre -Set Memory System. Be an ar-ti-san. Write for our free brochure. AOK Manufacturing. Inc., Box 445, Kenmore, WA 98028.

WRITE US AND WE'LL SEND YOU THE BEST CATALOG YOU EVER READ! No kidding. Speakerlab's catalog took longer to write than some of our competitors have been in business. In fact, we created an industry by

"building great kits so you can afford great speakers.- Our catalog is an

01413,:unctaluable ion anual of speaker

it will introduce you to

inv

the finest speaker kits made

dP / anywhere...with the strongest money -back guarantee. Find out for yourself...FREE. FREE,

that is. Write now. Right now.

eekeda Dept. C -PE, 735 N. Northlake Way Seattle, WA 98103

THE BEST CB ANTENNA SEND FOR FREE PAL FULL LINE

CATALOG AND DECAL

PAL Antenna Corp. 2614 EAST ADAMS PHOENIX. ARIZONA 85034

POLICE/FIRE SCANNERS, crystals, antennas, CBs. Radar Detectors. HPR, Box 19224, Denver, CO 80219.

CB RADIOS, VHF -UHF Scanners, Crystal, Antennas, Radar Detectors. Wholesale. Southland, Box 3591, Baytown, TX 77520.

BARGAINS GALORE! Buy -sell -trade classifieds in "Elec- tronics Trader" only 108 word! Send $2.00 for next four issues. Electronics Trader, Darwin, CA 93522.

TRANSISTORS FOR C -B Repair. IC's and diodes TV audio repairs 2$C756A - $2.40, 2SC1306 - $2.95, 2SC1307 - $3.85, PLLOZAG - $7.50, AN239 - $5.50, STK439 - $8.95. Many more. FREE Catalog and transistor. B&D Enter- prises, Box 32, Mt. Jewett, PA 16740.

CIRCUIT BOARD from production -ready artwork. Free details. QUANTITY discounts. CM CIRCUITS, 22 Maple Ave., Lackawanna, NY 14218.

UNSCRAMBLE CODED MESSAGES from Police, Fire

and Medical Channels. Same day service. Satisfac- tion guaranteed. Don Nobles Electronics, Inc., Rt. 7,

Box 265B, Hot Springs, Arkansas 71901. (501) 623-6027.

MONTHLY PICTURE FLYER. Quality Surplus Electronic parts. Low Prices. Star-Tronics. Box 683, McMinnville, OR 97128.

PRINTED CIRCUIT supplies, chemicals, tools, artwork, plat- ing solutions. Major credit cards. Catalog $1.00, refundable. CIRCOLEX. Box 198, Marcy, NY 13403.

RECONDITIONED TEST EQUIPMENT $1 00 for catalog. WALTER'S TEST EQUIPMENT, 2697 Nickel, San Pablo, CA 94806, (415) 758-1050.

ELECTRONIC PARTS, Tubes, Semiconductors, Phonograph Needles. FREE CATALOG. Rey Enterprises. Box 1539, Hialeah, FL 33011.

CHEMICALS. Lab Supplies. Lowest prices, fastest service anywhere. Listing 258. Westech Corp.. Box 593. Logan, Utah 84321.

LOW. LOW Component Prices! Ask for free flyer. Write: EEP, 11 Revere Place, Tappan. NY 10983.

NEGATIVE ION GENERATORS AND ACCESSORIES. (Kits). Fascinating details -$1.00. Golden Enterprises, Box 1282 -PE, Glendale, Arizona 85311.

Super PoweAul Wireless Mic j

:. . 10 times more powerful than other mics. ' -

Transmits up to ,h mile to any FM radio. I '

I

Easy to assemble kit. 15V battery (not incl.) .4

t. ,

Call (305) 725-1000 or send $1&953 51.00 ,re 2.T ., aNppkq to u51 Corp, P.O. Dox PE -2062, MNbouma,FL32901,C001eocE-2For $18.95 catalog of transmitters, voice scramblers Oir th.r ..on

and other specialty items, enclose $2.00 to USI Corp. "*"'-.',""7'47.,'**"R x."7.7.7--7.

RENT, LEASE, SELL TVS! Guaranteed complete system $15.00. Perrys' Rental Systems. Box 1407, Santa Maria, CA 93456.

CANADIAN - SURPLUS ELECTRONIC PARTS. Free flyers & samples. Special: Tantalum 47uf 20VDC. 10 for $1.00. G. Paquette, 2264 Gagnon Rd., Blainville, Que., Canada. U.S. Inquiries.

ELECTRONIC components/hardware grabbag, $20 value for $3. G.F. Mumenthaler Ind., P.O. Box 853, Bonita, CA 92002.

VIDEO TAPE L-500 Beta, $14.00 each, 20 for 5240.00. Good buys on other types. 408-224-0606.

ADJUSTABLE FREQUENCY OSCILLATOR CIRCUIT drives 180mH to 16v. Assembled -tested. $5.50 guaranteed. K3 Elec- tronics, Box 100, Athens, NY 12015.

OPTO ELECTRONIC DEVICES, laser diodes, LED's, fiber optics for experimenter and electronic enthusiast. For free information, write: Eastern Elec- tronics, P.O. Box 2204, Clifton, NJ 07015.



VIDEO CASSETTES - Large Selection - Pre-recorded, all

ratings, for VHS & BETA. Also blank cassettes, L-500 @ $14.00, L-750 @ $19.00, VK-250 @ $19.00, in lots of 10 or more. We accept MC and VISA. Send for free catalog. Parker Electronics, 123P Dutchess Turnpike, Poughkeepsie, NY 12603.

BUYERS SPECIALS - Bearcat 250 $279.00. Bearcat 111

High Band with all crystals $115.00, 12 Volt 4 Amp Regulated Power Supply $14.50. Cobra Modulated Mic. $8.95. Many more closeouts and specials. Send $2.00 for complete list. R

& L ELECTRONICS, 2923 20th St.. Rockford, III. 61109.

nSFITELLITE TU GET 50 CHANNELS! ll

It's all true! No matter where you eve .. receive movies. sports. pay lelev,sron. sports !tom around the drld! 24'h u

loorgleirrgrrIranill sources and des q information. send 57.95

SPACECOAST RESEARCH New

Dept. D. P.O. Box 442. Altamonte Springs, FL 32701

PRINTED CIRCUIT BOARDS, your artwork. 450 sq. in. single sided, 602 sq. in. double sided. Mail your order now, or send for free details. Digitronics, P.O. Box 2494, Toledo. OH 43606.

SCANNERS, VIDEO RECORDERS. C.B.'s. All brands discounted. Bearcat 250, $279.95. S.A.S.E. (large) speeds prices. McDonald Electronics, Box 1385(W). Rohnert Park, CA 94928. (707) 544-4388.

ELECTRONIC SURVEILLANCE (Bugs/Taps) COUNTER- MEASURES. Technical articles. List $1.00. Ross, 18114

Kftchenhouse, Germantown. MD 20767.

VIDEO TAPE VHS VK250, 10 for $169.50. Beta L -500's. 10

for $119.50. We ship anywhere. Video Hotline, (408) 224- 0606. MC/VISA.

COSMAC ELF II OWNERS: display any register or memory location on TV. Fantastic debugging aid. Manual $6.00. Cas- sette & manual $16.00. K. Meyer, 20412 Mauer. St. Clair Shores, MI 48080.

PLANS AND KITS

AMAZING ELECTRONIC ,

4 PRODUCTS ifs LASERS SUPER POWERED, RIFLE. PISTOL, POCKET SEE IN DARK . PORO.

TECHNICAL. DEBUGGING UNCRAMBLERS GIANT TESLA STUNWAND IV

DISRUPTER . ENERGY PRODUCING, SCIENTIFIC DETECTION, ELECTRIFYING,

CHEMICAL. ULTRASONIC, CB. AFRO. AUTO AND MECH DEVICES. HUNDREDS -y

MORE ALL NEw PLUS INFO UNITD PARTS SERVICE

CATALOG El

INFORMAT ION unrimilMA Dept. E8, Box 716, Amherst, NH 03031

I' 1

FREE KIT Catalog contains Test and Experimenter's

Equipment. Dage Scientific Instruments, Box

1054P, Livermore, CA 94550.

TIGER 500 SIMPLI-KIT

FOR THE DO-IT-YOURSELFER NOW! a high quality CD ELECTRONIC IGNITION SYSTEM in kit form. Contains all components and solder to build complete Solid -State Electronic CD Ignition System for your car. Assembly requires less than 3 hours.

increases MPG 15% Eliminates 4 or 5 tune-ups Increases horsepower 15% Instant starting, any Plugs and Points last weather 50.000 miles Dual system switch

Fits only 12 volt neg. ground... Only $26.95 postpaid

Star Corporation P.O. Box 1727 Grand Junction. Colorado 81501

TV -OSCILLOSCOPE CONVERTER externally adapts TV into audio frequency oscilloscope. Info. $1.00, Plans $7.50. with P.C. $15.00, TV -1 VHF modulator $12.00, kit $60.00. Evolutronics. Box 855-F, San Rafael, CA 94902.

CB/HAM ACCESSORIES. kits. parts. construction plans - catalog. Omnipolarized antenna, 300 MHz counter, Modula- tion booster. Plans $3.00 each, 57.50 all. PANAXIS, Box 130-A4, Paradise, CA 95969.

BUILD YOUR OWN n

' SYMPHONY FJ OF SOUND!

° ° 4 It's fun and easy -takes just minutes a day!, Complete kits for organs, pianos, strings, rhythms, amplifiers, synthesizers. Also

Pfacory assembled. 104 -page ' catalog $2.00

OWER5I Wersi Electronics, Inc.

Dept. ZD. 1720 Hempstead Road Lancaster, PA 17601

FREQUENCY COUNTERS 50 MHZ $59.95. 500 MHZ $79.95. Flashing LED's $1.00. Digital clocks 512.95. Lec- tronix, Box 42. Madison Heights. Michigan 48071.

PRINTED CIRCUIT Boards from sketch or artwork. Kit pro-

jects. Free details. DANOCINTHS Inc., Box 261, Westland. MI

48185.

PROTECT electrical devices from unauthorized use. New

patented circuit is cheap. easy to build. uses no power. Plans/ instructions direct from inventor. $3.50. SEOSWITCH-PE. Box 1084, San Mateo. CA 94403.

TAPE - SLIDE Synchronizer. multiprojector. hp -dissolve plans. $5.50. Audiovisual group. $8.50. Millers. 1896 Maywood, S.Euclid. OH 44121.

!/N; flame or fuss pliers or tools $1500 reguired2r

+ $1.00 postage and handling Jewelers - Hobbyists

For Fun or $$$ ,/f DO IT YOURSELF Instructions included. Must be electroplated.

Burglar. Fire'.Smoke Alarm Catalog,

Billions of dollars lost annually due to lack of protective warning alarms.

FREE CATALOG Shows you how to protect your home, business and person. Wholesale prices. Do-it-yourself. Free

engineering service.

Burdex Security Co.

Box 82802 PE -049 Lincoln, Ne. 68501 tl

PROFESSIONAL ALARM SYSTEMS and supplies at wholesale prices. FREE CATALOG. CAPCO. Box 5980- CPE4, Incline Village, Nevada 89450.

VEHICLE STOLEN - CAN BE LOCATED. "Information" Pro-

tect automobile, boat, trailer, airplane, home, office. Fowler Alarms, Box 64466 -PEI. Los Angeles, CA 90064.

MUSICAL INSTRUMENTS

UP TO 60% DISCOUNT. Name brand instruments catalog. Freeport Music, 114 G, Mahan St.. W. Babylon, N.Y. 11704.

HIGH FIDELITY

DIAMOND NEEDLES and Stereo Cartridges at Discount prices for Shure. Pickering. Stanton, Empire, Grado and ADC. Send for free catalog. LYLE CARTRIDGES. Dept. P. Box 69.

mow Kensington Station. Brooklyn. New York 11218. For Fast Ser -

I vice call Toll Free 800-221-0906. 1 L / CUSTOM CASSETTE RECORDERS. 4 track. half -speed.

Cassettes .ast four times as long! Also Time Compression: listen doube speed without pitch change. Free catalog. SFB PRODUCTS, Box, E-385. Wayne. PA 19087.

NOW!!!You can build and plate 14Kt, 18Kt heavy / abstract edges on any stone and create !ewelry, plate baby shoes, baseballs, leaves, flowers, acorns, etc. Information and instruction sheets only $1.00.

GOLD EDGE 7117 3rd Ave. /Box P/Dept. GM

Scottsdale, AZ 85251/16021994-5752

WELDING -BURNING LASER -$9.00, Five Laser Plans - $8.00, Laser Light Show -$19.00, "Wild Ideas" Catalog - $2.00. Solaser, "PE79". Box 1015. Claremont, CA 91711.

DOLBY ADD-ON ENCODES/DECODES RECORDINGS. FM. Quality components, complete kit. Calibration tapes. Comprehensive test report. PE -A INTEGREX, Box 747, Havertown. PA. 19083.

ELECTRONIC KITS under $5. includes wireless mics., electronic sirens, alarms. etc. Brochure. Electrokit. 5 Redwood. Milford, Mass. 01757.

GIANT TV PROJECTION. Shows like $1000's projector. Lens kit $14.95. Plans $1.00. Projeco. 829 Flatbush. Brooklyn. NY 11226.

GIANT SCREEN TV. Same components as $2000-$4000 sets. Plans, 3 element lens. and washable screen $329. Plans only $5 (deductible from order). Video Projection. P.O. Box 158, Lake Zurich. IL 60047.

TOP QUALITY IMPORTED KITS. IC's. foreign transistors. Free catalog. International Electronics, Box 567. Williamsville, NY 14221.

TELEPHONES & PARTS

TELEPHONES UNLIMITED, Equipment Supplies. All

types, Regular, Keyed, Modular. Catalog 50 cents.

Box 1147E, San Diego, California 92112.

OMAK PHONE CENTER. All types of telephones - keyed, modular and decorator. Catalog $1.00 (refundable). Box 38, Beardstown, IL 62618. (217) 323-3963.

ALARMS

QUALITY BURGLAR -FIRE ALARM EQUIPMENT at discount prices. Free Catalog! Steffens, Box 624K, Cranford, N.J. 07016.

WANTED

GOLD. Silver. Platinum, Mercury. Tantalum wanted. Highest prices paid by refinery. Ores assayed. Free circular. Mercury Terminal, Norwood, MA 02062.

WANTED! CB DEALERS AND DISTRIBUTORS

PAL Antenna Corp. 2614 EAST ADAMS - PHOENIX. ARIZONA 85034

MARANTZ RC4 Remote Control for 4 -channel receiver. Post- age paid. 64 Parklands Rd. Chichester. Sussex. U.K.

TUBES

RADIO & T.V. Tubes -36 cents each. Send for free Catalog. Cornell, 4213 University. San Diego. Calif. 92105.

TUBES: "Oldies". Latest. Supplies. components. schematics. Catalog Fee (stamp appreciated). Steinmetz, 7519 -PE Ma-

plewood, Hammond. Ind. 46324.

11UBES-RECEIVING. Industrial and Semiconductors Factory Boxed. Free price sheet including TV, Radio and audio parts 161. Transleteronic. Inc.. 1365 39th St.. Brooklyn, New York 11218. Telephone: (212) 633-2800. Toll free: 800-221-5802.

RADIO AND TV TUBES 1938 to 1978 $1.00 ea. PRELLER TV. Augusta. AR 72006. (501) 347-2281.

GOVERNMENT SURPLUS

MANUALS for Govt Surplus radios. test sets, scopes. List 50

cents (coin). Books. 7218 Roanne Drive, Washington. D.C.

20021.

JEEPS -559.30! - CARS -$33.50! - 200,000 ITEMS! - GOVERNMENT SURPLUS - Most COMPREHENSIVE DI- RECTORY AVAILABLE tells how, where to buy - YOUR AREA - $2.00 - MONEYBACK GUARANTEE - Govern- ment Information Services, Department GE -60, Box 99249, San Francisco, California 94109 (433 California).

APRIL 1979 113


GOVERNMENT SURPLUS. Buy in your Area. How, where. Send $2.00. Surplus, 30177 -PE Headquarters Building, Washington, D.C. 20014.

"GOVERNMENT SURPLUS DIRECTORY." Buy 250,000 items (including Jeeps) ... low as 28 on dollar! Most complete information available - $2.00. Surplus Disposal, Box 19107 -HD, Washington, DC 20036.

INSTRUCTION

UNIVERSITY DEGREES BY MAIL! Bachelors, Mas-

ters, Ph.D's. Free revealing details. Counseling, Box

311-PE04, Tustin, California 92680.

LEARN WHILE ASLEEP! HYPNOTIZE! Astonishing details, strange catalog free! Autosuggestion, Box 24-ZD, Olympia, Washington 98507.

INTENSIVE 5 week course for Broadcast Engineers. FCC First Class license. Student rooms at the school. Radio En gineering Inc., 61 N. Pineapple Ave., Sarasota, FL 33577.

1979 "TESTS - ANSWERS" for FCC First Class

License. Plus - "Self Study Ability Test." Proven!

$9.95 Unconditional Moneyback Guarantee. Com-

mand Productions, Box 26348-P, San Francisco, CA

94126.

MATHEMATICS. ELECTRONICS. Advanced mathematics. Engineering mathematics. Digital Technology.

Free catalog. IHSI, Box 1189, Panama City, FL

32401.

PASS FCC EXAMINATIONS - 1st - 2nd - 3rd -Radar. Prov- en method by Victor Veley, noted author -teacher. Part I,

Workbook consisting of hundreds of problems with complete solutions. Part II, Question and Answer Manual has hundreds of practice questions. Complete course - Both Manuals, $14.95 postpaid. Oeffinger Publishing, Box 1240. Garden Grove, Calif. 92642.

RADIO BROADCASTING: Become DJ. engineer. Start your own station - investment/experience unnecessary! Receive free equipment, records. Free details. Broadcasting, Box 130-A4. Paradise, CA 95969.

ASSEMBLING HEATHKIT VTVM? Plentiful detail photos. au- diocassette instruction increase your success, satisfaction. Only $9.75. postpaid. Specify IM5218 or IM5228. The Instruc- tion Company. P.O. Box 2646, Stanford, CA 94305.

MICROCOMPUTERS

RADIO SHACK Authorized Sales Center Special 10% savings on catalog prices including TRS-80. Free delivery on orders over $75.00. 1117 Conway. Mission, TX 78572.

MICROCOMPUTER OWNERS. Thousand programs loaned free. Try before buy. SASE for listing. TREND IV. Box 7433. Hollywood, FL 33021.

FOR INVENTORS

PATENT AND DEVELOP Your invention. Registered Patent Agent and Licensed Professional Engineer, Send for FREE PATENT INFORMATION every inventor should have. Richard L. Miller, P.E., 3612 Woolworth Building, New York, NY 10007. (212) 267-5252.

HAVE YOU AN INVENTION? We evaluate, develop,

improve and market meritorious inventions and

ideas. For free brochure write, call: Inventors Guild,

P.O. Box 411, Fort Washington, PA 19034. (215)

233-5252.

BUSINESS OPPORTUNITIES

I MADE $40,000.00 Year by Matlorder! Helped others make money! Torrey, Box 318 -NN, Ypsilanti, Michigan 48197.

GET RICH!!! Secret law erases debts. Free report exposes millionairé $$ secrets. blueprints, No. EE4, 453 W. 256, NYC 10471.

MECHANICALLY INCLINED INDIVIDUALS WANTED -

Assemble electronic devices in your home. Get started in spare time. Experience, Knowledge or Investment Not Necessary. Expect big profits: $300 - $600/Wk. Possible. Write for free literature telling how.

ELECTRONIC DEVELOPMENT LAB BOX 1560PE, Pinellas Park, FL 33565

BORROW $25,000 "OVERNIGHT." Any purpose. Keep indefinitely! Free Report! Success Research, Box 29263 GC, Indianapolis, Indiana 46229.

$1200.00 MONTHLY Correcting Pupils' Lessons!!! Stan Im- mediately. Free Report. Send self-addressed stampea envelope. Home, Box 98201-SJXM, San Diego, CA 92109.

BEAT THE RACES! Free Booklet! "Unlimited Lifetime Income From Thoroughbreds - Harness". Elias, Box 47BB, Brooklyn, NY 11219.

WHAT'S BEHIND OVER 1,000 opportunity offers. Free details. Allied American, 5217C Sydney, Port Orange, FL 32019.

HOW TO MAKE $100 weekly/kitchen table! Free brochure. Brooks, Box 68-ZD, Ouenemo, KS 66528.

BE YOUR OWN BOSS. Your own metalizing business FREE. We supply all equipment and know how. Free details. Write: Mason, Room MC -376 -ID, 1512 Jarvis, Chicago, IL 60626.

PERSONALS

MAKE FRIENDS WORLDWISE through international correspondence, illustrated brochure free. Hermes-Verlag. Box 110660/Z, D-1000 Berlin 11, Germany.

EMPLOYMENT OPPORTUNITIES

ELECTRONICS/AVIONICS EMPLOYMENT OPPOR- TUNITIES. Report on jobs now open. Details FREE. Aviation Employment Information Service. Box 240E. Northport, New York 11768.

RADIO -TV JOBS ... Stations hiring nationwide! Free details: "Job Leads", 1680 -PG Vine. Hollywood, CA 90028.

ELECTRONIC TECHNICIANS: Government job listing 8 In- structions, $10.00. World Air Data, Dept. -E, Box 5706, Der - wood, MD 20855.

POPULAR ELECTRONICS INDEXES For 1977 now available. Prepared in cooperation with the Editors of "PIE," this index contains hundreds of references to product tests, construction projects, circuit tips and theory and is an essential companion to your magazine collection. 1977 Edition, $1.50 per copy. All editions from 1972 onward still available at the same price. Add $.25 per order for postage and handling. $.50 per copy, foreign orders. INDEX, 6195 Deer Path, Manassas, Va. 22110.

FANTASTIC! TV facts booklet as seen on NBC T.V. $1.00, guaranteed. DVS, Box 912E, Smithtown, NY 11787.

HOBBIES

333 WORLD STAMPS 1111 Genuine AMERICANA postage stamps.,,,, _

collection from Seychelles,Grenadine, Malagasy -many more. PLUS hundreds of others of interest. 812.00 CATALIN: VA II' I; Other fine stamps enclosed for your . 14NTK,u9j

inspection.FRAsEx Ca, in. [to, PE49 White Plains N.Y. 10601

MOTION PICTURE FILMS

WELCOME SPRING WITH MUSIC! Frolic & fun with "Thor- oughly Modern Millie" (Julie Andrews) 17:44 S-8 Color/Snd, $49.95 (save $6.). Shirley MacLaine stars in "Sweet Charity", wistful memorable musical, 17.00, $48.95. Jesus Christ Superstar 17:18 S-8 color/snd. spectacular, innovative, shot in Israel. $46.95. Big name westerns: Rory Calhoun "Flaming Guns"; Glen Ford "Cowboy"; John Wayne "The Cowboy & the Girl"; James Stewart "Frontier Fun" - S-8 B/W Silent 200' action films, ltd quant., $9.95 ea PPD. "The Big Surf' spec. 200' S8 Eastman color - ride the waves with Hawaii's best: only $16.95 ea PPD. News Headlines In the '70's, last chance for collectors. '71 News Parade (Nixon, Kissinger, Open Door to China); '73 News (Watergate & energy crisis); '74 News (Nixon resigns, Ford pres.. Cyprus Battle, Peron dies); '75 Spectacular, 38th annty. news - $8.95 ea + 352 ship. Ltd Quan. Added features - Movies Great Headlines - Hindenburg, Pearl Harbor, Tacoma Bridge collapse. Famous lights. S8 B/W Snd 200' action reels (1) Marciano -Louis & Moore -Jackson + 2 bouts. (2) Ali -Williams & Johnson-Ketchel (1909); Zale-Graziano + Ross -Armstrong; $18.95 ea PPD (save $3. film). Universal 64-pg catalog $1.20 (foreign $2.). Columbia, Sportlite, Universal, Ring Classics order forms 358 ea with flyers. SPORTLITE FILMS. Elect -4/79, Box 24-500, Speedway. IN 46224.

HYPNOTISM EMPLOYMENT INFORMATION CENTER: Information for all 50 states and Canada. Send $1.00 for details. J. Fraser, Dept. FREE Hypnotism. Self -Hypnosis. Sleep Learning Catalog! C, 208 S. 4th, De Soto. MO 63020. Drawer H400, Ruidoso. New Mexico 88345.

DO-IT-YOURSELF

MODULAR TELEPHONES now available. Sets and components, compatible with Western Electric concept. Catalog 50 cents. Box 1147W, San Diego, California 92112.

AUDIO ANALOG/SYNTHESIS. Plans, parts, kits, etc. for the most exciting sound projects ever. Get on our mailing list, send 258 to: CFR Associates Inc., Newton, N.H. 03858.

COMPLETE LINE Security Systems for home, Busi-

ness. Send self addressed, stamped envelope. Dar -

bar, Box 1147E, San Diego, CA 92112.

UNBELIEVABLE: 850 page Tool and Supply Catalog for Tradesmen, Craftsmen, Hobby or Recreational Endeavors. 60,000 items. $5.00 refundable. McKilligan, PE479, Johnson City. NY 13790.

REAL ESTATE

BIG ... FREE ... SUMMER CATALOG! Over 2,600 top values coast to coast!! UNITED FARM AGENCY, 612 -EP, West 471h, Kansas City, MO 64112.

FREE CATALOGS. Repair air conditioning, refrigeration. RUBBER STAMPS Tools. supplies, full instructions. Doolin, 2016 Canton, Dallas, Texas 75201.

RUBBER STAMPS, BUSINESS CARDS. Many new prod -

NEW LUXURY Car Without Cost. Free Details! Codex-ZZ, ucts. Catalog. Jackson's. E-100, Brownsville Rd., Mt. Vernon. III. 62864.

Box 6073, Toledo, Ohio 43614.

MECHANICALLY INCLINED individuals desiring ownership of Small Electronics Manufacturing Business - without investment. Write: BUSINESSES. 92-K2 Brighton 11th, Brook- lyn, New York 11235.

BOOKS AND MAGAZINES

FREE book prophet Elijah coming before Christ. Wonderful MILLIONS in Mail!!! Free Secrets. Transwo!ld-17. Box 6226. bible evidence. MEGIDDO Mission, Dept. 64, 481 Thurston Toledo, OH 43614. Rd., Rochester, N.Y. 14619.

MISCELLANEOUS

MPG INCREASED! Bypass Pollution Devices easily. RE- VERSIBLY!! Free details - Posco GEE4, 453 W. 256, NYC 10471.

COLOR TRANSPARENCIES without photography or artistry. Easy 2step process! Enables PC board etching direct from magazine layouts, in minutes ... Kit $3.95. "Holographics", P.O. Box 323, Yellowsprings, OH 45387.

CB RADIO OPERATORS - Send your name, handle and license number. We will inscribe this information attesting to your status as a CB operator on a handsome scroll, suitable for framing. Send information printed or typed together with check or money order for $4.95 to: Larry Bergman, P.O. Box 281, Cedarhurst, NY 11516.

STOP WASTING MONEY, start saving, lowest prices guaranteed: LCD Chrono Alarm Watch $55, TI -30 Calculator $14, Wahl 150 -Tip $12. MOST EVERYTHING ... Details $1. S.A.S.E. to Creatik, Box 926. Tulsa, OK 74101.

prices. anyone

1979 STEREO DIRECTORY & BUYING GUIDE

All the latest information on stereo and quadraphonic systems and components for your home. A

complete guide to more than 2500 products in all -with complete specifi cations, descriptions and

PLUS bonus feature articles. A must for concerned with good sound.

Order from STEREO DIRECTORY, Dept. 01053, P.O. Box 273, Pratt Station, Brooklyn, New York 11205. Enclose $3.00` ($2.50 plus 50C for postage and handling). 'Residents of CA, CO. DC, FL, IL, MI, MO, NY STATE, and VT add applicable sales tax.



Popular Electronics MA1003 CLOCK AND CASE SPECIAL: $19.95!

ADVERTISERS INDEX

READER SERVICE NO. ADVERTISER PAGE NO.

1 Aaron Gavin Instruments 14

2 Active Electronic Sales Corporation 96 3 Ancrona Corp 111 4 AP Products Incorporated 71

26 Apple Computer Cover 2

6 Audio-Technica U.S., Inc. 6

7 B&F Enterprises 115 8 Byte 66

58 Chafitz Electronics 12

Cleveland Institute 91

Electronics, Inc. 24, 25, 26, 27 9 Cobra, Product of Dynascan 15 10 Communications Power, Inc. 84 61 Computique 88 11 Contemporary Marketing 41

12 Continental Specialties Corporation 2

13 Cooper Group, The 82

60 DAK Industries 69 14 Digi-Key Corporation 109

Digital Research Corporation 111

15 DSI Instruments, Inc. 73 16 Douglas Dunhill 8

17 Edlie Electronics 110 18 Electronics Book Club 7

19 Fisher Corporation 17

20 Fluke 49 21 Fordham Radio Supply 102 22 Formula International 97

23 General Engines 105 24 Godbout Electronics, Bill 115 25 Grantham College of Engineering 95

5 Heath Company 18, 19

27 Heath Company 89, 90, 91

28 Hewlett-Packard 34 57 Hickok Electrical Instrument Cover 3 29 Hobby World 100

Howard Sams 56

30 IE Integrated Electronics 100 31 Illinois Audio 88 32 Integrated Circuits 104 33 International Components

Corporation 110 34 International Electronics

Unlimited 105

35 J & R Music World 88 JS & A National Sales Group . 1

36 Jameco Electronics 98, 99

37 Kedman Company 86

38 Maxell Corp. of America 39 Micro Computer Mart 92

39 Mini Micro Mart 75 59 Motorola Cover 4

McGraw-Hill 60, 61, 62, 63 40 McIntosh Laboratory, Inc. 77

National Technical Schools 78, 79, 80, 81

41 Netronics R&D Ltd. 75 42 Netronics R&D Ltd. 87 43 New -Tone Electronics 102

NRI Schools 42, 43, 44, 45

44 Ohio Scientific Instrument 5 45 OK Machine & Tool Corporation 50

46 PAIA Electronics, Inc. 84 47 PAL "Firestik" Antenna

Corporation 85 56 Panasonic 116 48 Percom Data Company, Inc. 14 49 Poly Paks 106

50 Quest 103

Radio Shack 67, 101

Sabtronics International, Inc. 10

55 Shure Brothers, Inc. 65 51 Solid State Sales 100 52 Southwest Technical

Products Corp. 95 Speakerlab, Inc. 85

53 Technics by Panasonic 46 54 Trans Island Production Ltd. 83

LOW POWER, FULLY STATIC

COMPUTER MEMORY - NOW

WITH BANK SELECT VERSIONS! Econorams" are generally available as unkits (sockets,

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S -t00 2 MHz S139 5159 N/A S-100 4 MHz 5295 5329 5429

118 2 MHz $200 5270 N/A

S-100 4 MHz S445 5485 5605

Dig Grp 4 MHz 5649 N/A N/A

S-100 4 MHz $599 5649 5789

SBC 4 MHz N/A N/A S1050

NEW! BANK SELECT ECONORAMS 16K ECONORAM XIIr" S-100 4 MHz 5369 S419 5519

24K ECONORAM XII'" S-100 4 MHz S479 5539 5649

32K ECONORAM XIII'" 5-100 4 MHz 5629 $699 5849

NEW! FULL FUNCTION S-100 DUAL CHANNEL

I/O BOARD $189 unkit, $249 assm Our new I/O board gives you unparalleled flexibility

and operating convenience. Includes dual LSI hardware

MARTS, precisicn Baud rates up to 19.2 KBauo,

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we think you'll choose ours over any other.

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TERMS: loow 55s x1009.11, excess rebind«, GI rea 000 lax

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address for UPS Prices 90oá Ilvoegh cover nOniO of magatme A 5I to

orders under 5l5

Easy to build - just add 12V DC and time setting switches. Includes xtal timebase, ideal for mobile automotive use. 4 blue-green flourescent readouts. Case includes filter and .

mountirg hardware, and is available separately for 55.95. MA1003 module available separately for 516.50.

12V 8A POWER SUPPLY $44.50

12A @ 50% duty cycle, foldback current limiting. crowbar overvoltage protection, many more features. For transceivers, portable tape/TV equipment, disk drives, etc. Easy to build; except for transformer, diodes, and filter caps, alf parts mount on heavy-duty circuit board. Does not Include case.

TRS-80 CONVERSION KIT $109 (31$320)

Upgrades 4K machine to 16K, or populates Memory Expansion Module - our easy to follow instructions show you how. Dip shunts included. Chips have 250 ns access time for 4

MHz operation and are warranted for 1 year. Also expands memory in APPLE and Exidy Sorcerer computers.

HOT-OFF-THE.PHESSES-CATALOGUE: Our new catalogue is

something you need if yaur're into electronics. Parts, kits, computers electrode music. specials ... it's really packed, and

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FLOOR/SPEAKER SYSTEM r

001 -- :rte D 7c C D

ti TTY MD33. . . ASR .5348.88 D

TTV M033. . . KSR . .5288.88 y TTY .MD33. . . RO . .$248.88 IA

TTY MD35. . . ASR . .5448.88 TTY MD35. KSR 5388.88 m DEC . PDPBM . . . . 51488.88 ÌBM 7251/O-W/Keyboard .$498.88 ñ Singer MD70 Work Station I/O yours for only 5298.88 Singer Pertee 7 -Track Key To Tape 4311 Com.. , . . .5228.88 Singer Line Printer MD52 . . .5350.00 Nova IBM Desk Top Term,. 5748.88 Nova/IBM Desk Top Terminal

(ASCII) $888.88 Viatron System 21 . 5495.00

IBM SELECTRIC (BALL) PRINTER

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Special Offer! I COMPUTER STUFF r -- ̂ m r:

3 -WAY Bookshelf System Big enought to utilize full size speakers: 10" woofer, 5" middler & 4" super tweeter. Big enough to handle 50 Watts/channel, small enough to fit your budget. Freq. Resp. 30 t0 22,000 Hr. Ferro -Fluid Damping. Cabinet size 2Ox11x91/2"dp. Good things come In small packages - a nice extra set for the other room,.? Sh. Wt. 60 Lbs. (allow for two 30 Lb parcels) $88.8$/Pr. KIT Order No. 8'10542

>B 16/8 WATT STEREO AMP.

$5.78

.5.2

Neal assernblied board contains all solid state components & a DARLINGTON drive, push-pull output, all with Cum elementary power tab transistors & mounted to large heat sinks- Accepts Input from tape decks, magnetic or ceramic phono cartridges, mikes, etc. Requires a 48V transformer & 1 meg volume control. (cot supplied). Output 8 into 8 ohms. (supplied with data). Sh. Wt. 1 Lb. . . . 8'10513. . . 55.78 / Stereo Xforrrier, . .800530 , . $2.E8 I Stereo Pkg - 16 watts W/xformer and controls. Sh. Wt. 4 Lbs.. . . 8E0544, . . 513.38

o 3 m

RACK CABINETS Size: 24"X24"X68 " with rails on front & back for mounting equipment on 19" centers. No doors or sides List price $185.00 - NEW SURPLUS! Your cost only $50.00 each. qty Ltd. Fee, Collect. 78820469 -

P

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3Line-11 Line, with rotary dial, reconditioned, Please state choice! Sh. WI 10 Lbs . 3 Line 8C30277 $29.88 Sh. Wt 15 Lbs .11 Lone. 8C0550 .$49.88 A LSO: TOUCH ONE-PAV TTO TELEPHONES!

T , , 8C30273..S..$69AI.8N8

POWER SUPPLY KITS ot-

'1411' We supply all electrical and electronic

Parts, you supply labor & mechanical Parts, tools, & case. Battery Charger 12VDC, 20A, 20 Lbs 7C70005 . (20A) . . . . $19.50 Battery Charger 12V DC, 15A, 15 Lbs. 9C0089. . . .(15A). . $14.50 NI -Cad Battery Charger Klt, Super Buy! Up to 35VDC, 50OMa. Sh. Wt. 5 Lbs.. . .7C70243. . . $6.00 ' Logic P.S. Kit. 5V, 1A. Re9'ted 7C70267 3+

56.00 5 TO 24VDC Rc9'ted & adiustable m

'5 amps. Sh 175. 15 Lbs6M160301 $14.88 e

,TERMS: Add Postage - NO C,O,D's please n

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Phone Orders And

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AE/MC/Visa Call Us At

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1 VISA'

VISIT OUR NEW STORE! the "TOWNE DUMPE" en

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CIRCLE READER SERVICE CARD FOR FREE JUMBO CATALOG *; CIRCLE NO. 7 ON FREE INFORMATION CARD


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Turtle in Sit -back. And travel: the workfwith Panasonic's shirtwa gradfos-the Cámmartd Series. Setyour itirerarp b) si nuly setting -

the dial, Get the news from - Br¿ain cri theBBBC. Be in Peking when they announce:

1

o i .z.. r_ ., ;

--.4.9,..-:-.1-',.; 4 'F':::`-

thé new_pclng order. Or visit old friends in the o - d -

country Any aid country. Et/ern the good of U.SA Afluoyescentall-band readqut in!the RF-2900

(shown above) and the deluxe RF-4900 makes it easy to tind thousands of overseas and domestic short- wa-yi tralns-nissonsas well as AM, FM and CB. -ha Patásoric fluorescent digital display is accurate to within t kHz. That's accuracy!

And if you v;ant to hear more, both models give E - C=6CLE- 10. 5i Cad

F3 RF-Gain Co',trol bo enhance $

weak, distent stati»s or to prevér>_<t óvérload distcirfibr -

from overst tang s-aáions. The C....-rmand Series from Paiiason- .You can

travel the vexid without ever teaUing home. *Short Wave otscAptien will with antenna, weatherCoaditioñs.

operators geo3 .Diic.localian and other factors. Mn outside antºme may be regtired for masirsJri short wave recepfo t. -

Panasonic® just slightty ahead of our time.

FREE IFFORMATICN EAU 1 - .

_-a out$lrve.

all RF=4 you more. tike SSB (sing e -

sídeband) arflateur redid_ All 40 CB channels. Evn Morse r

-r. _ - communications. -And, of coursea_ -_- , = there's AM and FM. _ É

º, _-e - And like our de-uxe steel waver - t receiver, the RF-2900 haslan


ALL THE MOST WANTED FEATURES

AT A MOST WANTED RICE... 31G %z" HIGH LCD DISPLAY

JSE INDOORS OR OUT

200 HOUR 9V BATTERY LIFE

LUTO ZERO, POLARITY, OVERRANGE I 'DICATI'DN 400 mV DC F.S. SENSITIVITY

19 RANGES AND FUNCTIONS

Removable cover stores test lead set furnished as part of the unit.

-

Available accessories include A:, adapter, padded vine carrying case. 40KV DC probe, 10 5n7 DC shLnt.

X10 DCV probe adap er.availabie for protecting input -F to 10KV.

-

,

n ffF V/13y1

SPECIFICATIONS:

DC VOLTS (E RANGES): 0.1 nV to 1000V; .Accuracy ±0.5% rdg 5% f.s.; Input rrlDed: 10M ci; Max. input 1kV exlpt 500V on 2COmV range. AC VOLTS (40Hz to 5<Hz): 0.1 J to 600V; /accuracy: ±1.0% rdg ±0.5% f.s. (-2dB max. at 5kHz:; Max. input: 600V. RESISTANCE (6 LOW POWER RANGES):O.1cito 20Mí1; Accu acy: ±0.5% rdg +0.5% f.s. (±i-.5% rdg on 20Mci range); input protécted :0 120VA_ ál ranges: DC CURRENT ;6 RANGES)-01n'A to'100niA Accuracy: ± I .C% rdg DIMENSION 3 AND WEIGHT: 5-7/8" x 3 -?/8" x 1-3/4", 8 oz.;POWER_ 9V battery -(not included) or Hickok AC adapter; READ RATE: 3/sec.

HICKOW_ - LX 3031

n 600V ma a z10V ilOclf l000v 'RV dc max la

ar;,

HICKOK Here is the handfull of accuracy you've been waiting for. Hand- somely encased.

Compact. Efficient. Only 8 ounces. Hickok's exciting, new LX 303, 31

digit Mini-Multime- ter with high quality components, one year guarantee and rugged Cyco- lac® case offers

features previously found only in ex --

pensive units...at a price under $75.00!

So why wait any longer? The

amazing LX 303 is here, NOW!

Another American made test equip-

- ment breakthrough from Hickok, The Value Innovator. Order today!

SFe yóur local Hickok distributor or order below

Send Check or Money Crde to = O. Box 220BP _-- Culver City. Calif. 90230. Ca itorr 3 residents adC

6% sal as Mx. Add $3.00 to corer co :tag.. and handling Maste- Ch: rge and Visa welcomed. Plea:. include your

char 3e nar, cumber, Interbank numoer and -.potation date

CALIFORNIA ANCRONA 11680 ellerso l Blvd Culver C,ty, CA 90230

1213) 39o-3595 1300 E Ed,n9yr Ave, Santa Ana, CA 92705

17141 547-8425 1054E El Cam no Rnsl Sunnyvale. CA 94087

1408) 243.4121

PHONE ORDERS: 213-641-4064

PLEASE OEND ME Hickok LX303 Digital Mull meters ............. . @ 74.95 ea. RC -3 AC Adapter, 1 - 5VAC (220VAC aCki .) ... .. . @ 7.50 ea.

CC -3 Deluxe CarryyinC Ca ._........._ ..........._ @ 7.50 ea. VP -10 X10 DCV Probe Adapter @14.95ea. CS -1 10 ADC Currant Shrlt @ 14.95 ea. VP -40 40 KV D.O. Prole ... ..... @ 35.00 ea.

Narre

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TEXAS ANCRONA

2649 R,onmond Ave Nouslory TX 77398

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Tacyrn, A_ B5711 Atlanta. GA 30105 Porllend, OR 9792-4 Vancouver, B C 05W 204

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CIRCLE NC, 57 DN FREE INFORMATION CARD


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ANL ELECTRÓSCAN

MI MAX o... LOAD CLEAR MEM

!ntroducing Electroscan. A quiet CB radio! We finally built a CB so complete, there's which lets you search quickly for either an

only one popular feature it doesn't have. available, open channel to continue your con - Radio Hash. You know, the irritating noise versation ... or the nearest occupied channel

you hear every time your squelch is wide open. to locate other CB'ers. Because Motorola's exclusive VariCom® Besides these features, Electroscan also

noise elimination system combines RF and IF offers the Extender® noise blanker and fully gain to selectively reduce noise on the channels. variable noise limiter. Plus variable control/ It trims away radio hash for cleaner operation, dynamic gain microphone that adjusts mic gain especially when the squelch is wide open and over a 20 db range to make your voice sound you're listening really hard. better.

The Electroscan's microprocessor also has So stop in today at a Motorola' Dealer and the convenient programmable memory which take a look at the Electroscan, the first CB that allows you to set, in the sequence you desire, virtually eliminates radio hash. any 10 channels you enjoy listening to everyday. MOTOROLA

The Electroscan also offers a ,scanner . . . . cE3

To find the dealer nearest you, write: Market Relations Manager, Motorola, Inc., Automotive Products Division, 1299 East Algonquin Road, Schaumburg, Illinois 60196. 8, Motorola, VariCom, and Extender are registered trademarks of Motorola Inc.



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WORLD'S LARGEST -SELLING ELECTRONICS … · Soviet chess champion agrees to endorse American chess computer in surprise w u . answer to computer challenge. The JS&A Chess Computer